A method for forming a compound on a substrate is provided. The method includes depositing a composition onto a surface of a substrate; illuminating the composition and the substrate with pulsed energy; melting the substrate and decomposing the composition simultaneously; and forming a compound on the substrate. A first component of the compound is derived from the substrate and a second component of the compound is derived from the composition.

Material and antireflection structure designs and methods of manufacturing are provided that produce efficient photovoltaic power conversion from single- and multi-junction devices. Materials of different energy gap are combined in the depletion region of at least one of the semiconductor junctions. Higher energy gap layers are positioned to reduce the diode dark current and enhance the operating voltage by suppressing both carrier injections across the junction and recombination rates within the junction. Step-graded antireflection structures are placed above the active region of the device in order to increase the photocurrent.

A photovoltaic solar cell comprises a nano-patterned substrate layer. A plurality of nano-windows are etched into an intermediate substrate layer to form the nano-patterned substrate layer. The nano-patterned substrate layer is positioned between an n-type semiconductor layer composed of an n-type semiconductor material and a p-type semiconductor layer composed of a p-type semiconductor material. Semiconductor material accumulates in the plurality of nano-windows, causing a plurality of heterojunctions to form between the n-type semiconductor layer and the p-type semiconductor layer.

A system and method of patterning dopants of opposite polarity to form a solar cell is described. Two dopant films are deposited on a substrate. A laser is used to pattern the N-type dopant, by mixing the two dopant films into a single film with an exposure to the laser and/or drive the N-type dopant into the substrate to form an N-type emitter. A thermal process drives the P-type dopant from the P-type dopant film to form P-type emitters and further drives the N-type dopant from the single film to either form or further drive the N-type emitter.

Embodiments of a photovoltaic device are provided herein. The photovoltaic device can include a layer stack and an absorber layer disposed on the layer stack. The absorber layer can include a first region and a second region. Each of the first region of the absorber layer and the second region of the absorber layer can include a compound comprising cadmium, selenium, and tellurium. An atomic concentration of selenium can vary across the absorber layer. The first region of the absorber layer can have a thickness between 100 nanometers to 3000 nanometers. The second region of the absorber layer can have a thickness between 100 nanometers to 3000 nanometers. A ratio of an average atomic concentration of selenium in the first region of the absorber layer to an average atomic concentration of selenium in the second region of the absorber layer can be greater than 10.

Embodiments of a photovoltaic device are provided herein. The photovoltaic device can include a layer stack and an absorber layer disposed on the layer stack. The absorber layer can include a first region and a second region. Each of the first region of the absorber layer and the second region of the absorber layer can include a compound comprising cadmium, selenium, and tellurium. An atomic concentration of selenium can vary across the absorber layer. The first region of the absorber layer can have a thickness between 100 nanometers to 3000 nanometers. The second region of the absorber layer can have a thickness between 100 nanometers to 3000 nanometers. A ratio of an average atomic concentration of selenium in the first region of the absorber layer to an average atomic concentration of selenium in the second region of the absorber layer can be greater than 10.

A multijunction solar cell including an upper first solar subcell having an emitter and base layers forming a photoelectric junction; a second solar subcell disposed under and adjacent to the upper first solar subcell, and having an emitter and base layers forming a photoelectric junction; and a third solar subcell disposed under and adjacent to the second solar subcell and having an emitter and base layers forming a photoelectric junction; wherein at least one of the base and emitter layers of at least a particular solar subcell from among the upper first solar subcell, the second solar subcell, and the third solar subcell has a graded band gap throughout at least a portion of thickness of its active layer adjacent to the photoelectric junction and being in a range of 20 to 300 MeV greater than a band gap in the active layer in both the emitter layer and the base layer spaced away from the photoelectric junction.

A multijunction solar cell including an upper first solar subcell having an emitter and base layers forming a photoelectric junction; a second solar subcell disposed under and adjacent to the upper first solar subcell, and having an emitter and base layers forming a photoelectric junction; and a third solar subcell disposed under and adjacent to the second solar subcell and having an emitter and base layers forming a photoelectric junction; wherein at least one of the base and emitter layers of at least a particular solar subcell from among the upper first solar subcell, the second solar subcell, and the third solar subcell has a graded band gap throughout at least a portion of thickness of its active layer adjacent to the photoelectric junction and being in a range of 20 to 300 MeV greater than a band gap in the active layer in both the emitter layer and the base layer spaced away from the photoelectric junction.

According to an embodiment, a photoelectric conversion device includes an emitter electrode, an anode electrode, an insulator, and a fixed charge portion. The emitter electrode receives incident light having a predetermined wavelength and emits electrons. The anode electrode absorbs the electrons. The insulator supports the emitter electrode and the anode electrode. The fixed charge portion generates an electric field for giving the electrons a potential to help to jump out from the emitter electrode and move toward the anode electrode.

According to an embodiment, a photoelectric conversion device includes an emitter electrode, an anode electrode, an insulator, and a fixed charge portion. The emitter electrode receives incident light having a predetermined wavelength and emits electrons. The anode electrode absorbs the electrons. The insulator supports the emitter electrode and the anode electrode. The fixed charge portion generates an electric field for giving the electrons a potential to help to jump out from the emitter electrode and move toward the anode electrode.