Abstract: A semiconductor device that utilizes intraband photon absorption in quantum dots to provide a capacitive photodetector. The presence of the quantum dots creates confined energy states within the photodetector device. Electrons are trapped in these confined energy states. When the photodetector is illuminated by light having an appropriate photon energy, the stored electrons are released to the conduction band, causing a change in the capacitance of the photodetector. By measuring this change in capacitance, light incident on the photodetector can be detected and quantified.

Abstract: A semiconductor device that utilizes intraband photon absorption in quantum dots to provide a capacitive photodetector. The presence of the quantum dots creates confined energy states within the photodetector device. Electrons are trapped in these confined energy states. When the photodetector is illuminated by light having an appropriate photon energy, the stored electrons are released to the conduction band, causing a change in the capacitance of the photodetector. By measuring this change in capacitance, light incident on the photodetector can be detected and quantified.

Abstract: An energy storage system is provided. The energy storage system includes a vessel made of a refractory material and containing a phase change material, a thermally insulating cover at least partially surrounding the vessel, an emitter, made of a refractory material, having a first side arranged to be heated by the phase change material and a second side intended to radiate thermal power, at least one photovoltaic cell arranged to receive the thermal power emitted by the second side of the emitter, and electric means for heating the phase change material.

Abstract: A solar cell comprises a three layer semiconductor structure wherein the top (14) and middle (15) layer are made of a semiconductor of higher bandgap than the bottom layer (16), the middle layer (15) has a higher dopant concentration than the top layer (14), and the three layer semiconductor structure is either a p-n-p structure or an n-p-n structure. The solar cell includes three terminals or contacts: a top contact (17) contacting the top layer (14), a middle contact (18) contacting the middle layer (15) and a bottom contact (19) contacting the bottom layer (16). Light anti-reflecting layers and semiconductor layers to reduce surface recombination can also be added to the basic three layer semiconductor structure.

Abstract: An intermediate band solar cell is provided. The intermediate band material of the intermediate band solar cell consists of a collection of quantum dots of a semiconductor material that are immersed in a volume of a second semiconductor material. The first semiconductor material has a rock salt-type crystalline structure, and the second semiconductor material has a zinc blende structure. The quantum dots are produced by the immiscibility of the first semiconductor material in the second semiconductor material. A combination of the first and second semiconductor materials with a very similar lattice constant can therefore be selected such that the layer of intermediate band material does not have mechanical stress accumulation.

Abstract: Method for manufacturing of optoelectronic devices based on thin-film, intermediate band materials, characterized in that it comprises, at least, the following steps: a first stage wherein a substrate (1) is coated with a metal layer acting as electrode (2); a second stage, whereby atop the metal layer (2) a p-type semiconductor (3) is deposited; and a third stage, whereby the intermediate band material is processed; and wherein such an intermediate band material comprises nanoscopic structures (4) of multinary material of the type (Cu,Ag)(Al,Ga,In)(S,Se,Te)2 embedded in a matrix (5) of a similar composition, except for the absence of, at least, one cationic species present in the nanostructure.

Abstract: This invention describe a process for obtaining thin films of intermediate band semiconductor materials consisting of obtaining a target of compressed particles of the said material for its use in sputtering equipment. The target is obtained by means of the thermal process of a mixture of semiconductor material components, following a specific profile of temperatures and times, in order to obtain a material in a polycrystalline form of the same composition as the intermediate band semiconductor material. The polycrystalline material is disintegrated again by means of mechanical processes in the form of a powder and is then compacted, through the application of a suitable pressure in order to form a target.

Abstract: It consists of a quantum dot intermediate band solar cell with light coupling by diffraction. In the structure of the cell, the rear metalic contact (7) is separated from the semiconductor (1) by a low refraction index layer (8). It also contains a number of grooves (9) on the front face covered by one or more antireflecting layers (10) which are also part of the diffractive structure. The grooves (9) are designed in such a way that they difract on the infrared range the light cone coming from a concentrator, leaning them as much as possible. In this way, the luminous electromagnetic power flux is increased facilitating its absorption by the quantum dot layer (4). Layer (8) produces a total internal reflection of the rays inclined by (9).

Abstract: Procedure to obtain semiconductor materials with electronic levels close to the mid-bandgap (deep levels) which do not suffer from the non-radiative recombination by multiple phonon emission (MPE) associated to the existence of that kind of levels. The procedure consist in doping by any means the semiconductor with a density sufficiently high of the impurities producing the deep level, so that a Mott transition of the electron wavefunctions representing the localized states in the impurities is induced, in such a way that these wavefunctions become distributed across the whole semiconductor and are shared by all the impurities. When this happens, local charge density variations, and thus non-radiative recombination by MPE, disappear. Based on the resulting materials (semiconductors with three separate energy bands and radiative behavior (1), (2) and (3)) different optoelectronic devices can be fabricated (solar cells, photodetectors, lasers, etc.

Abstract: The invention relates to a solar cell containing a semiconductor (1) with an intermediate band (2) that is half filled with electrons, located between two layers of ordinary n type (3) and p type (4) semiconductors. When lighted, electron-hole pairs are formed either by a photon that absorbs the necessary energy (5) or by two photons (6,7) that absorb less energy which pump an electron from the valence band to the intermediate band (8) and from the latter to the conductance band (9). An electrical current is generated that exits on the p side and returns via the n side. The n and p layers also prevent the intermediate band from contacting the outer metal connections, which would have resulted in a short-circuit. Said cell converts solar energy into electricity in a more efficient manner than conventional cells and contributes to improvement of the photovoltaic devices.