Abstract: A chemical sensor including a substrate, an on-chip lens layer, and a flattening layer. On the substrate, a plurality of photodiodes are formed and arranged in a planar form. The on-chip lens layer collects incident light to the photodiodes and is provided on the substrate. The flattening layer covers and planarizes the on-chip lens to form a probe holding surface for holding a probe material.

Abstract: A method of manufacturing a solar cell is disclosed. The method includes forming a doping region including first and second portions having different doping concentrations by ion-implanting a dopant into a semiconductor substrate and forming an electrode connected to the doping region. In the forming of the doping region, the first and second portions are simultaneously formed by the same process using a mask that is disposed at a distance from the semiconductor substrate.

Abstract: Among other things, one or more image sensors and techniques for forming such image sensors are provided. An image sensor comprises a photodiode array configured to detect light. A filler grid is formed over the photodiode array, such as over a dielectric grid. The filler grid comprises one or more filler structures, such as a first filler structure that provides a light propagation path to a first photodiode that is primarily through the first filler structure. In this way, signal strength decay of light along the light propagation path before detection by the first photodiode is mitigated. The image sensor comprises a reflective layer that channels light towards corresponding photodiodes. For example, a first reflective layer portion guides light towards the first photodiode and away from a second photodiode. In this way, crosstalk, otherwise resulting from detection of light by incorrect photodiodes, is mitigated.

Abstract: A method of manufacturing a solid-state imaging apparatus, comprising preparing a substrate on which photoelectric conversion portions are arranged, forming inner lenses corresponding to the photoelectric conversion portions, and forming microlenses corresponding to the photoelectric conversion portions, wherein the forming inner lenses includes forming, on the substrate, a dielectric film for forming the plurality of inner lenses, and etching second portions of the dielectric film around first portions serving as central portions of the inner lenses while leaving upper faces of the first portions, so as to form curved faces or inclined faces connected to the upper faces.

Abstract: Disclosed are a method of forming a photodetector and a photodetector structure. In the method, a polycrystalline or amorphous light-absorbing layer is formed on a dielectric layer such that it is in contact with a monocrystalline semiconductor core of an optical waveguide. The light-absorbing layer is then encapsulated in one or more strain-relief layers and a rapid melting growth (RMG) process is performed to crystallize the light-absorbing layer. The strain-relief layer(s) are tuned for controlled strain relief so that, during the RMG process, the light-absorbing layer remains crack-free. The strain-relief layer(s) are then removed and an encapsulation layer is formed over the light-absorbing layer (e.g., filling in surface pits that developed during the RMG process). Subsequently, dopants are implanted through the encapsulation layer to form diffusion regions for PIN diode(s). Since the encapsulation layer is relatively thin, desired dopant profiles can be achieved within the diffusion regions.

Abstract: Apparatuses capable of and techniques for detecting long wavelength radiation are provided.

Abstract: A detection apparatus includes a plurality of conversion elements, an interlayer insulating layer, and a covering layer. Each of the plurality of conversion elements includes an electrode electrically connected to a corresponding one of a plurality of switching elements and a semiconductor layer disposed on the electrode. The interlayer insulating layer is disposed so as to cover the plurality of switching elements and composed of an organic material, and has a surface including a first region and a second region located outside the first region. The electrodes are disposed on the surface of the interlayer insulating layer in the first region. The covering layer is disposed on the surface of the interlayer insulating layer in the second region and composed of an inorganic material.

Abstract: An imaging system may include an image sensor die stacked on top of a digital signal processor (DSP) die. The image sensor die may be a backside illuminated image sensor die. Through-oxide vias (TOVs) may be formed in the image sensor die and may extend at least partially into in the DSP die to facilitate communications between the image sensor die and the DSP die. Bond pad structures may be formed on the surface of the image sensor die and may be coupled to off-chip circuitry via bonding wires soldered to the bad pad structures. Color filter elements may be formed over active image sensor pixels on the image sensor die. Microlens structures may be formed over the color filter elements. An antireflective coating (ARC) liner may be simultaneously formed over the microlens structures and over the bond pad structures to passivate the bond pad structures.

Abstract: A light-emitting element display device includes a substrate, one or a plurality of thin film transistors, a light-emitting element, a first electrode, and a second electrode. The substrate includes an insulating material. The thin film transistors are in each pixel of a display area on the substrate. The light-emitting element emits light by current flow in each pixel. The first electrode is between the substrate and the thin film transistors, and overlaps at least two of the thin film transistors when viewed in plan. The second electrode includes a conducting material, and is arranged across the first electrode from the substrate via an insulating film so as to form a capacitor together with the first electrode.

Abstract: An image sensor including a plurality of photodiodes disposed in a semiconductor layer and a plurality of deep trench isolation regions disposed in the semiconductor layer. The plurality of deep trench isolation regions include: (1) an oxide layer disposed on an inner surface of the plurality of deep trench isolation regions and (2) a conductive fill disposed in the plurality of deep trench isolation regions where the oxide layer is disposed between the semiconductor layer and the conductive fill. A plurality of pinning wells is also disposed in the semiconductor layer, and the plurality of pinning wells in combination with the plurality of deep trench isolation regions separate individual photodiodes in the plurality of photodiodes. A fixed charge layer is disposed on the semiconductor layer, and the plurality of deep trench isolation regions are disposed between the plurality of pinning wells and the fixed charge layer.

Abstract: Improved techniques are disclosed for fabrication of touch panels using thin sheet glass, coupling external circuitry, and securely holding the touch panel within a portable electronic device. The thin sheet glass may be chemically strengthened and laser scribed.

Abstract: A method for producing a spot-size convertor includes the steps of preparing a substrate; forming a stacked semiconductor layer including first and second core layers on the substrate; forming a mesa structure by etching the stacked semiconductor layer using a first mask, the mesa structure including a side surface and a bottom portion of the first core layer; forming a protective mask covering the side surface; etching the bottom portion using the protective mask to form a top mesa; and forming a bottom mesa by etching the second core layer using a second mask. The top mesa includes the first core layer and a portion having a mesa width gradually reduced in a first direction of a waveguide axis. The bottom mesa includes the second core layer and a portion having a mesa width gradually reduced in a second direction opposite to the first direction.

Abstract: Provided is a radiation detecting element, including: needle crystal scintillators and a protruding pattern in which: one end of the needle crystal scintillators is in contact with of upper surfaces of the multiple protrusions; a gap corresponding to a gap between the multiple protrusions is provided between portions of the needle crystal scintillators in contact with the upper surfaces of the multiple protrusions; and a number of the needle crystal scintillators in contact with one of the upper surfaces is 5 or less. Conventionally, since the needle crystals exhibit a state of a polycrystalline film in an early stage of vapor deposition, and light also spreads in a horizontal direction, the light received by a photodetector portion and the spatial resolution was lower than ideal values. The present invention enables the deviating region to be the ideal state in an early stage of growth.

Abstract: In an image sensor in which each microlens of a microlens array is disposed at a position corresponding to each pixel on a side to which light flux is incident, a layer formed of a member different from a member constituting the microlens array is disposed on the side of the microlens array to which light flux is incident, and a surface of the layer formed of the different member has a phase structure optically-opposite to that of the microlens array.

Abstract: A device includes a diode, which includes a first, a second, and a third doped region in a semiconductor substrate. The first doped region is of a first conductivity type, and has a first impurity concentration. The second doped region is of the first conductivity type, and has a second impurity concentration lower than the first impurity concentration. The second doped region encircles the first doped region. The third doped region is of a second conductivity type opposite the first conductivity type, wherein the third doped region overlaps a portion of the first doped region and a portion of the second doped region.

Abstract: A solar cell includes a support substrate, a back electrode layer on the support substrate, a light absorbing layer on the back electrode layer, a buffer layer on the light absorbing layer, a high resistance buffer layer on the buffer layer, and a front electrode layer on the high resistance buffer layer. An insulating part is located on a top surface of the light absorbing layer. A method of fabricating the solar cell includes forming the back electrode layer on the substrate, forming the light absorbing layer on the back electrode layer, forming the buffer layer on the light absorbing layer, oxidizing a top surface of the buffer layer, and forming the front electrode layer on the buffer layer.

Abstract: Embodiments relate to detector imaging arrays with scintillators (e.g., scintillating phosphor screens) mounted to imaging arrays or radiographic detectors using the same. For example, the detector imaging arrays can include a scintillator, an imaging array comprising imaging pixels, where each imaging pixel comprises at least one readout element and one photosensor; and a first dielectric layer formed between the scintillator and the imaging layer, wherein the dielectric constant of the insulating layer is very low. Embodiments according to the application can include a second dielectric layer formed over at least a portion of the non-photosensitive regions of the array and/or a first dielectric layer, each with a dielectric constant.

Abstract: Some embodiments include an imaging system. The image sensor array includes multiple image sensor sheets configured in an array grid. Each image sensor sheet of the multiple image sensor sheets can include a flexible substrate layer, and the flexible substrate layer can include a first flexible substrate side and a second flexible substrate side opposite the first flexible substrate side. Meanwhile, each image sensor sheet of the multiple sensor sheets can include multiple image sensors over the first flexible substrate side, the multiple image sensors can include multiple flat panel image detectors configured in a sheet grid, and the image sensor array can include an approximately constant pixel pitch. Other embodiments of related systems and methods are also disclosed.

Abstract: Solar devices with high resistance to light-induced degradation are described. A wide optical bandgap interface layer positioned between a p-doped semiconductor layer and an intrinsic semiconductor layer is made resistant to light-induced degradation through treatment with a hydrogen-containing plasma. In one embodiment, a p-i-n structure is formed with the interface layer at the p/i interface. Optionally, an additional interface layer treated with a hydrogen-containing plasma is formed between the intrinsic layer and the n-doped layer. Alternatively, a hydrogen-containing plasma is used to treat an upper portion of the intrinsic layer prior to deposition of the n-doped semiconductor layer. The interface layer is also applicable to-multi-junction solar cells with plural p-i-n structures. The p-doped and n-doped layers can optionally include sublayers of different compositions and different morphologies (e.g., microcrystalline or amorphous).

Abstract: A device for detecting a surface plasmon and polarization includes: a topological insulating layer formed on a substrate; first and second electrodes formed on the topological insulating layer; and a waveguide connected to the topological insulating layer between the first and second electrodes.

Abstract: A color light-emitting diode using a blue light component to produce red light and green light is disclosed. A blue-light emitting material is provided between a cathode layer and an anode layer for emitting the blue light component. A light re-emitting layer has a first material in a first diode section arranged to produce a red light component in response to the blue light component, and a second material in a second diode section arranged to produce a green light component in response to the blue light component. A transparent material in a third diode section allows part of the blue light component to transmit through. The anode layer is partitioned into three electrode portions separately located in the three diode sections, so that the red, green and blue light components in the diode sections can be separately controlled.

Abstract: A solid-state imaging device includes a photodetector which is formed on a substrate and is configured to generate signal charge by photoelectric conversion, a floating diffusion configured to receive the signal charge generated by the photodetector, a plurality of MOS transistors including a transfer transistor that transfers the signal charge to the floating diffusion and an amplification transistor that outputs an pixel signal corresponding to a potential of the floating diffusion, a multi-wiring layer which is formed in a layer higher than the substrate and is composed of a plurality of wiring layers electrically connected to the MOS transistors via contact portions, and a light-shielding film that is constituted by a bottom wiring layer disposed in a layer higher than the substrate and lower than the multi-wiring layer.

Abstract: An organic light emitting diode (OLED) display device and a method of fabricating the same are provided. The OLED display device includes a substrate having a thin film transistor region and a capacitor region, a buffer layer disposed on the substrate, a gate insulating layer disposed on the substrate, a lower capacitor electrode disposed on the gate insulating layer in the capacitor region, an interlayer insulating layer disposed on the substrate, and an upper capacitor electrode disposed on the interlayer insulating layer and facing the lower capacitor electrode, wherein regions of each of the buffer layer, the gate insulating layer, the interlayer insulating layer, the lower capacitor electrode, and the upper capacitor electrode have surfaces in which protrusions having the same shape as grain boundaries of the semiconductor layer are formed. The resultant capacitor has an increased surface area, and therefore, an increased capacitance.

Abstract: An image sensor includes first to fourth microlenses. A first height difference between a first valley between the first and second microlenses and tops of the first and second microlenses is larger than a second height difference between a second valley between the third and fourth microlenses and tops of the third and fourth microlens, a first angle formed by a tangent in an outermost portion of the first microlens, which contacts the first valley and a plane perpendicular to the normal is equal to or smaller than a second angle formed by a tangent in an outermost portion of the third microlens, which contacts the second valley and the plane.

Abstract: Various embodiments may relate to a device for the surface treatment of a substrate, including a processing head, which is mounted rotatably about an axis of rotation, and which comprises multiple gas outlets, which are at least partially implemented on a radial outer edge of the processing head.

Abstract: A solid-state image sensor includes a semiconductor substrate having a photoelectric conversion element converting incident light into a charge and a charge retaining section temporarily retaining the charge photoelectrically converted by the photoelectric conversion element and a light shielding section having an embedded section extending in at least a region between the photoelectric conversion element and the charge retaining section of the semiconductor substrate.

Abstract: The finding that with a reasonable effort a layer thickness and/or refractive index variation may be acquired which realizes different internal optical path lengths for impinging radiation whereby fluctuation of spectral sensitivity of the photodetector is reduced is used to provide image sensors with a less fluctuating spectral sensitivity with respect to different wavelengths, or photodetectors with a small fluctuation of the spectral sensitivity from photodetector to photodetector with respect to defined wavelengths, with a reasonable effort.

Abstract: A method for producing a spot size converter includes the steps of forming a first insulator mask on a stacked semiconductor layer; forming first and second terraces, and a waveguide mesa disposed between the first and second terraces by etching the stacked semiconductor layer using the first insulator mask, the first terrace having first to fourth terrace portions, the second terrace having fifth to eighth terrace portions, the waveguide mesa having first to fourth mesa portions; forming a second insulator mask including a first pattern on the first terrace portion, a second pattern on the fifth terrace portion, a third pattern on the third and fourth mesa portions, and a fourth pattern that integrally covers a region extending from the fourth terrace portion to the eighth terrace portion through the fourth mesa portion; and selectively growing a semiconductor layer by using the second insulator mask.

Abstract: Disclosed are a solar cell and a method of fabricating the same. The solar cell includes a first back electrode layer on a support substrate; a second back electrode layer on the first back electrode layer; a light absorbing layer on the second back electrode layer; and a front electrode layer on the light absorbing layer.

Abstract: A CIGS solar cell having a flexible substrate based on improved supply of Na. The CIGS solar cell includes a substrate formed of a flexible material, a rear electrode formed on the substrate, a CIGS light-absorption layer formed on the rear electrode, a buffer layer formed on the CIGS light-absorption layer, and a front electrode formed on the buffer layer, wherein the rear electrode comprise a single-layered Na-added metal electrode layer. A single-layered Na-added Mo electrode layer, specific resistance of which is about 1/10th the specific resistance under conditions of a process of forming a typical multilayer rear electrode, is applied to the rear electrode, thereby providing a CIGS solar cell having a flexible substrate and high conversion efficiency.

Abstract: A method of forming a photonic device and resulting structure are described in which the photonic device is epitaxially grown over a substrate surface vertically, and laterally over trench isolation regions formed in the substrate surface.

Abstract: A solar panel includes a solar cell assembly formed of at least two solar cells arranged adjacent to one another, the cells each having a solar-facing surface, a gap area between them and patterned with busbars on their solar-facing surface. The solar-facing surface includes active regions and inactive regions and is covered by a layer of transparent material having an inner side and an outer side, the inner side disposed adjacent to the solar facing surface of the assembly and the outer side defining an outer surface of the panel. At least one optical member is disposed on the outer side of the layer and configured to substantially cover at least a portion of the inactive regions of the solar-facing surface and to deflect solar radiation impinging upon the optical member away from the inactive regions and onto the active regions of the solar-facing surface of the cell.

Abstract: A back-side illumination solid-state imaging apparatus, comprising a light-shielding member including a plurality of openings, and a plurality of pixels corresponding to the plurality of openings, wherein each pixel includes a photoelectric conversion portion, a microlens and an inner lens, the inner lens of a first pixel of an Mth row×an Nth column and the inner lens of a second pixel of an (M+1)th row×an (N+1)th column are separated from each other through a dielectric member, and the dielectric member contacts with part of the light-shielding member between a first opening corresponding to the first pixel and a second opening corresponding to the second pixel.

Abstract: A solid-state imaging device includes a plurality of photoelectric conversion portions each provided in a semiconductor substrate and receives incident light through a light sensing surface, and a pixel separation portion provided to electrically separate a plurality of pixels. At least a pinning layer and a light shielding layer are provided in an inner portion of a trench provided on a side portion of each of the photoelectric conversion portions in an incident surface side, the trench includes a first trench and a second trench formed to be wider than the first trench in a portion shallower than the first trench, the pinning layer is formed in an inner portion of the first trench to cover an inside surface of the second trench, and the light shielding layer is formed to bury an inner portion of the second trench at least via the pinning layer.

Abstract: A solid-state imaging device including a substrate; a wiring layer formed on a front side of the substrate in which pixels are formed; a surface electrode pad section formed in the wiring layer; a light-shielding film formed on a rear side of the substrate; a pad section base layer formed in the same layer as the light-shielding film; an on-chip lens layer formed over the light-shielding film and the pad section base layer in a side opposite from the substrate side; a back electrode pad section formed above the on-chip lens layer; a through-hole formed to penetrate the on-chip lens layer, the pad section base layer, and the substrate so as to expose the surface electrode pad section; and a through-electrode layer which is formed in the through-hole and connects the surface electrode pad section and the back electrode pad section.

Abstract: A method of making an electronic device comprising a double bank well-defining structure, which method comprises: providing an electronic substrate; depositing a first insulating material on the substrate to form a first insulating layer; depositing a second insulating material on the first insulating layer to form a second insulating layer; removing a portion of the second insulating layer to expose a portion of the first insulating layer and form a second well-defining bank; depositing a resist on the second insulating layer and on a portion of the exposed first insulating layer; removing the portion of the first insulating layer not covered by the resist, to expose a portion of the electronic substrate and form a first well-defining bank within the second well-defining bank; and removing the resist. The method can provide devices with reduced leakage currents.

Abstract: There is provided a solid-state imaging device which includes a plurality of pixels including an imaging pixel for generating a captured image and a focus detection pixel for detecting a focus, in which the focus detection pixel includes a microlens, a photoelectric conversion unit which receives light incident from the microlens, a light-shielding unit which shields a portion of light incident on the photoelectric conversion unit, and a dimming filter which dims the light incident on the photoelectric conversion unit and is formed to contain a black pigment. The present technology can be applied to, for example, a CMOS image sensor.

Abstract: A solid-state image pickup apparatus includes an image pickup pixel and a focus detection pixel. The image pickup pixel includes a micro lens and a photoelectric conversion unit that receives light incident from the micro lens. The focus detection pixel includes the micro lens, the photoelectric conversion unit, and a light shielding unit that shields part of light incident on the photoelectric conversion unit. In the solid-state image pickup apparatus, the micro lens is uniformly formed in the image pickup pixel and the focus detection pixel, and the focus detection pixel further includes a high refractive index film formed under the micro lens.

Abstract: An integrated waveguide structure with perforated chip edge seal and methods of manufacture are disclosed herein. The structure includes a guard ring structure surrounding an active region of an integrated circuit chip. The structure further includes a gap in the guard ring structure which is located at a predetermined level of the integrated circuit chip. The structure further includes a waveguide structure formed on a substrate of the integrated circuit chip. The structure further includes a fiber optic optically coupled to the waveguide structure through the gap formed in the guard ring structure.

Abstract: Semiconductor devices and methods for fabricating semiconductor devices are provided. In one example, a method for fabricating a semiconductor device includes etching a trench into a waveguide layer in a detector region of a semiconductor substrate. An avalanche photodetector diode is formed about the trench. Forming the avalanche photodetector diode includes forming a multiplication region in the waveguide layer laterally adjacent to the trench. An absorption region is formed at least partially disposed in the trench.

Abstract: A light emitting device, a method of manufacturing the same, a light emitting device package, and a lighting system are disclosed. The light emitting device may include a first conductive semiconductor layer, a second conductive semiconductor layer, and an active layer interposed between the first and second conductive semiconductor layers. The first conductive semiconductor layer, the active layer, and the second conductive semiconductor layer may include Al. The second conductive semiconductor layer may have Al content higher than Al content of the first conductive semiconductor layer. The first conductive semiconductor layer may have Al content higher than Al content of the active layer.

Abstract: A solid-state imaging device includes a photoelectric transformation portion and a micro lens, the micro lens has a first refractive index layer which is a first refractive index and a second refractive index layer which is a second refractive index different from the first refractive index, wherein the micro lens is configured so that a vertical cross section, which is a surface perpendicular to the capturing surface, has a rectangular shape, wherein each of the first refractive index layer and the second refractive index layer are arranged adjacent to each other in a direction along the capturing surface, and an interface between the first refractive index layer and the second refractive index layer in the vertical cross section is formed so as to follow a direction perpendicular to the capturing surface.

Abstract: Provided are a semiconductor light emitting device and a method of fabricating the same. The semiconductor light emitting device includes: a light emitting structure comprising a first conductive type semiconductor layer, an active layer under the first conductive type semiconductor layer, and a second conductive type semiconductor layer under the active layer; a reflective electrode layer under the light emitting structure, and an outer protection layer at an outer circumference of the reflective electrode layer.

Abstract: Provided is a method whereby a cell for a light-emitting device less variable in the thickness of the internal space can be suitably produced with high production efficiency. A glass-made fused part forming element (25) is provided in a grid-like pattern between a pair of glass sheet base materials (21, 24) disposed facing each other with a space therebetween. The fused part forming element (25) is fused to each of the pair of glass sheet base materials (21, 24) to produce a cell base material (30) having a grid-like fused part (26). The cell base material (30) is cut along each of row and column directions of the grid-like fused part (26) to produce a plurality of light-emitting devices (1). Portions off the grid-like fused part forming element (25) along a first direction are formed of glass ribbons (22) and portions of the grid-like fused part forming element (25) along a second direction are formed of glass paste.

Abstract: An image sensor package includes an image sensor, a window, and a molding, where the molding includes a lens holder extension portion extending upwards from the window. The lens holder extension portion includes a female threaded aperture extending from the window such that the window is exposed through the aperture. A lens is supported in a threaded lens support. The threaded lens support is threaded into the aperture of the lens holder extension portion. The lens is readily adjusted relative to the image sensor by rotating the lens support.

Abstract: In one aspect, optoelectronic devices are described herein. In some embodiments, an optoelectronic device comprises a fiber core, a radiation transmissive first electrode surrounding the fiber core, at least one photosensitive inorganic layer surrounding the first electrode and electrically connected to the first electrode, and a second electrode surrounding the inorganic layer and electrically connected to the inorganic layer. In some embodiments, the device comprises a photovoltaic cell.

Abstract: A method of manufacturing a solar cell is disclosed. The method includes forming a dielectric film on a semiconductor substrate doped with a first conductive type impurity, exposing a high concentration doping region of a predetermined selective emitter by partially removing the dielectric film, and ion-implanting a second conductive type impurity into a front surface of the semiconductor substrate with the dielectric film formed thereon to form a high concentration doping layer in the semiconductor substrate to correspond to the high concentration doping region and to form a low concentration doping layer in the semiconductor substrate to correspond to a region in which the dielectric film is formed.

Abstract: An image sensor for capturing X-ray image data and optical image data includes an X-ray absorption layer and a plurality of photodiodes disposed in a semiconductor layer. The X-ray absorption layer is configured to emit photons in response to receiving X-ray radiation. The plurality of photodiodes disposed in the semiconductor layer is optically coupled to receive image light to generate the optical image data, and is optically coupled to receive photons from the X-ray absorption layer to generate X-ray image data.

Abstract: A method for manufacturing a solid-state image pickup device is provided. The image pickup apparatus includes a photoelectric conversion portion disposed on the semiconductor substrate, a first insulating film over the photoelectric conversion portion, functioning as an antireflection film, a second insulating film on the first insulating film, disposed corresponding to the photoelectric conversion portion, and a waveguide having a clad and a core whose bottom is disposed on the second insulating film. The method includes forming an opening by anisotropically etching part of a member disposed over the photoelectric conversion portion, thereby forming the clad, and forming the core in the opening. In the method, the etching is performed under conditions where the etching rate of the second insulating film is lower than the etching rate of the member.

Abstract: A method of manufacturing a solar cell includes forming a buffer layer between an optical absorption layer and a window electrode layer. Forming the buffer layer includes depositing a metal material on the optical absorption layer, supplying a non-metal material on the optical absorption layer, supplying a gas material including oxygen atoms on the optical absorption layer, and reacting the metal material with the non-metal material. The gas material reacts with the metal material and the non-metal material to form a metal sulfur oxide on the optical absorption layer.