Abstract: Techniques are disclosed by which electronic devices that include line-of-sight optical communication systems may become optically aware of other electronic devices and perform optical communication handshakes with other devices. An electronic device may use a motion sensor to record its posing when it determines, during the performance of an optical communication handshake, that it is pointed at the electronic device with which it is performing the optical communication handshake (or that the other electronic device is within a field of view of the electronic device). A recorded device posing, in combination with optical communications and motion sensor data, may also be used to map another device's location and enable a user of an electronic device to pan away from and break optical communication with the other device, then easily return to a recorded posing that enables a continuation of optical communications with the other device.

Abstract: An electronic device may have optical sensors. Control circuitry may use sensor measurements in controlling adjustable components and taking other actions. The optical sensors may be self-mixing sensors such as incoherent self-mixing sensors. One or more sensors may be used in gathering sensor measurements. In configurations in which an electronic device contain multiple self-mixing sensors, multi-wavelength measurements can be gathered using incoherent light sources in the sensors that operate a set of different wavelengths. The light source of each incoherent self-mixing sensor may be a superluminescent light-emitting diode, a resonant cavity light-emitting diode, or other amplified or non-amplified spontaneous emission source. Optical systems such as lenses in a housing for an electronic device may be aligned with the self-mixing sensors.

Abstract: An electronic watch includes a housing, a user-operable watch crown mounted to the housing, an electromagnetic radiation source emitting a beam of electromagnetic radiation toward a watch crown surface, and a sensor. The beam of electromagnetic radiation depends on a coherent mixing of electromagnetic radiation within a resonant cavity of the electromagnetic radiation source. The coherent mixing includes a mixing of a first amount of electromagnetic radiation generated by the electromagnetic radiation source and a second amount of electromagnetic radiation redirected into the resonant cavity by the watch crown surface. The sensor measures a first parameter of the beam of electromagnetic radiation and determines, using the measurement of the first parameter, a value of a second parameter characterizing movement of the watch crown. The second parameter may include a direction of rotation or speed of rotation of the watch crown, or other parameters.

Abstract: Disclosed herein are electronic devices having touch input surfaces. A user's touch input or press on the touch input surface is detected using a set of lasers, such as vertical-cavity surface-emitting lasers (VCSELs) that emit beams of light toward the touch input surface. The user's touch causes changes in the self-mixing interference within the VCSEL of the emitted light with reflected light, such as from the touch input surface. Deflection and movement (e.g., drag motion) of the user's touch is determined from detected changes in the VCSELs' operation due to the self-mixing interference.

Abstract: An electronic device such as an earbud may have control circuitry mounted in a housing. The housing may have portions such as an ear portion with a speaker port through which a speaker plays audio and a stalk portion that extends from the ear portion. Proximity sensors may be formed in the electronic device. For example, one or more proximity sensors may be formed on the ear portion to detect when a user has inserted an earbud into the ear of the user and/or one or more proximity sensors may be formed on a stalk portion to detect when a user is holding an earbud by the stalk or when a user is providing finger touch input such as taps, swipes, and/or other gestures on the stalk portion. The proximity sensors may be optical proximity sensors such as coherent self-mixing proximity sensors.

Abstract: A photovoltaic device and method include a substrate, a conductive layer formed on the substrate and an absorber layer formed on the conductive layer from a Cu—Zn—Sn containing chalcogenide material. An emitter layer is formed on the absorber layer and a buffer layer is formed on the emitter layer including an atomic layer deposition (ALD) layer. A transparent conductor layer is formed on the buffer layer.

Abstract: A photovoltaic device and method include a substrate, a conductive layer formed on the substrate and an absorber layer formed on the conductive layer from a Cu—Zn—Sn containing chalcogenide material. An emitter layer is formed on the absorber layer and a buffer layer is formed on the emitter layer including an atomic layer deposition (ALD) layer. A transparent conductor layer is formed on the buffer layer.

Abstract: A photovoltaic device and method include a substrate, a conductive layer formed on the substrate and an absorber layer formed on the conductive layer from a Cu—Zn—Sn containing chalcogenide material. An emitter layer is formed on the absorber layer and a buffer layer is formed on the emitter layer including an atomic layer deposition (ALD) layer. A transparent conductor layer is formed on the buffer layer.

Abstract: A photovoltaic device and method include a substrate, a conductive layer formed on the substrate and an absorber layer formed on the conductive layer from a Cu—Zn—Sn containing chalcogenide material. An emitter layer is formed on the absorber layer and a buffer layer is formed on the emitter layer including an atomic layer deposition (ALD) layer. A transparent conductor layer is formed on the buffer layer.

Abstract: An electronic device may be provided with a display. The display may have a display cover layer. The display may have an active area with pixels and an inactive area without pixels. An opaque masking layer such as a layer of black ink may be formed on the underside of the display cover layer in the inactive area. Windows may be formed from openings in the opaque masking layer. Optical components such as infrared-light-based optical components may be aligned with the windows. The windows may include coatings in the openings that block visible light while transmitting infrared light. The window coatings may be formed from polymer layers containing pigments, polymer layers containing dyes that are coated with antireflection layers, thin-film interference filters formed from stacks of thin-film layers, or other coating structures.

Abstract: An electronic device may have a display with a cover layer. A light-based component such as an infrared-light proximity sensor or other infrared-light-based component may be aligned with a window in the display cover layer. The window may block visible light and transmit infrared light. A coating in the window may include a thin-film filter formed from a stack of inorganic dielectric layers. The thin-film filter may block visible light and transmit infrared light. The coating may also include at least one layer of material such as a semiconductor material that absorbs visible light and that passes infrared light. This material may be interposed between the thin-film filter and the display cover layer. Antireflection properties and color adjustment properties may be provided using thin-film layers between the thin-film filter and the display cover layer.

Abstract: A method for forming a photovoltaic device includes forming a photovoltaic absorption stack on a substrate including one or more of I-III-VI2 and I2-II-IV-VI4 semiconductor material. A transparent conductive contact layer is deposited on the photovoltaic absorption stack at a temperature less than 200 degrees Celsius. The transparent conductive contact layer has a thickness of about one micron and is formed on a front light-receiving surface. The surface includes pyramidal structures due to an as deposited thickness. The transparent conductive contact layer is wet etched to further roughen the front light-receiving surface to reduce reflectance.

Abstract: An electronic device may have a display with a cover layer. A light-based component such as an infrared-light proximity sensor or other infrared-light-based component may be aligned with a window in the display cover layer. The window may block visible light and transmit infrared light. A coating in the window may include a thin-film filter formed from a stack of inorganic dielectric layers. The thin-film filter may block visible light and transmit infrared light. The coating may also include at least one layer of material such as a semiconductor material that absorbs visible light and that passes infrared light. This material may be interposed between the thin-film filter and the display cover layer. Antireflection properties and color adjustment properties may be provided using thin-film layers between the thin-film filter and the display cover layer.

Abstract: A photovoltaic device includes a first contact and a hybrid absorber layer. The hybrid absorber layer includes a chalcogenide layer and a semiconductor layer in contact with the chalcogenide layer. A buffer layer is formed on the absorber layer, and a transparent conductive contact layer is formed on the buffer layer.

Abstract: A photovoltaic device includes a first contact and a hybrid absorber layer. The hybrid absorber layer includes a chalcogenide layer and a semiconductor layer in contact with the chalcogenide layer. A buffer layer is formed on the absorber layer, and a transparent conductive contact layer is formed on the buffer layer.

Abstract: A photovoltaic device and method include a substrate, a conductive layer formed on the substrate and an absorber layer formed on the conductive layer from a Cu—Zn—Sn containing chalcogenide material. An emitter layer is formed on the absorber layer and a buffer layer is formed on the emitter layer including an atomic layer deposition (ALD) layer. A transparent conductor layer is formed on the buffer layer.

Abstract: A method for fabricating a photovoltaic device includes forming a film including titanium on a conductive layer formed on a substrate. An absorber layer is formed including a Cu—Zn—Sn containing chalcogenide compound with a kesterite structure of the formula: Cu2-xZn1+ySn(S1-zSez)4+q wherein 0?x?1; 0?y?1; 0?z?1; ?1?q?1 (CZTS) on the film. The absorber layer is annealed to diffuse titanium therein and to recrystallize the CZTS material of the film. A buffer layer is formed on the absorber layer, and a transparent conductive layer is formed on the buffer layer.

Abstract: A photovoltaic device and method include a substrate, a conductive layer formed on the substrate and an absorber layer formed on the conductive layer from a Cu—Zn—Sn containing chalcogenide material. An emitter layer is formed on the absorber layer and a buffer layer is formed on the emitter layer including an atomic layer deposition (ALD) layer. A transparent conductor layer is formed on the buffer layer.

Abstract: A method for fabricating a photovoltaic device includes forming a film including titanium on a conductive layer formed on a substrate. An absorber layer is formed including a Cu—Zn—Sn containing chalcogenide compound with a kesterite structure of the formula: Cu2-xZn1+ySn(S1-zSez)4+q wherein 0?x?1; 0?y?1; 0?z?1; ?1?q?1 (CZTS) on the film. The absorber layer is annealed to diffuse titanium therein and to recrystallize the CZTS material of the film. A buffer layer is formed on the absorber layer, and a transparent conductive layer is formed on the buffer layer.

Abstract: A method for fabricating a photovoltaic device includes forming a film including titanium on a conductive layer formed on a substrate. An absorber layer is formed including a Cu—Zn—Sn containing chalcogenide compound with a kesterite structure of the formula: Cu2-xZn1+ySn(S1-zSez)4+q wherein 0?x?1; 0?y?1; 0?z?1; ?1?q?1 (CZTS) on the film. The absorber layer is annealed to diffuse titanium therein and to recrystallize the CZTS material of the film. A buffer layer is formed on the absorber layer, and a transparent conductive layer is formed on the buffer layer.