A method for forming a photovoltaic device includes providing a substrate. A layer is deposited to form one or more layers of a photovoltaic stack on the substrate. The depositing of the amorphous layer includes performing a high power flash deposition for depositing a first portion of the layer. A low power deposition is performed for depositing a second portion of the layer.

A magnetically polarized photonic device is provided. The magnetically polarized photonic device (100) includes substrate (102), an annihilation layer (106) and a graded band gap layer (142). The annihilation layer (106) is deposed on a surface (104) of substrate (102) with graded band gap layer (142) disposed on annihilation layer (106). Contacts (116, 128) are disposed on ends (146, 150) of magnetically polarized photonic device (100). A magnetic field (159) is applied to graded band gap layer (142) and annihilation layer (106) to drive charges to contacts (116, 128).

A magnetically polarized photonic device is provided. The magnetically polarized photonic device (100) includes substrate (102), an annihilation layer (106) and a graded band gap layer (142). The annihilation layer (106) is deposed on a surface (104) of substrate (102) with graded band gap layer (142) disposed on annihilation layer (106). Contacts (116, 128) are disposed on ends (146, 150) of magnetically polarized photonic device (100). A magnetic field (159) is applied to graded band gap layer (142) and annihilation layer (106) to drive charges to contacts (116, 128).

A solar cell stack having a first semiconductor solar cell that has a p-n junction of a first material with a first lattice constant and a second semiconductor solar cell that has a p-n junction of a second material with a second lattice constant. The solar cell stack has a metamorphic buffer that includes a sequence of a first, lower layer and a second, center layer, and a third, upper layer, and includes an InGaAs or an AlInGaAs or an InGaP or an AlInGaP compound. The metamorphic buffer is formed between the first and second semiconductor solar cells and the lattice constant in the metamorphic buffer changes along the buffer's thickness dimension. The lattice constant of the third layer is greater than the lattice constant of the second layer, and the lattice constant of the second layer is greater than the lattice constant of the first layer.

Method of providing a boron doped region (8, 8a, 8b) in a silicon substrate (1), includes the steps of: (a) depositing a boron doping source (6) over a first surface (2) of the substrate (1); (b) annealing the substrate (1) for diffusing boron from the boron doping source (6) into the first surface (2), thereby yielding a boron doped region; (c) removing the boron doping source (6) from at least part of the first surface (2); (d) depositing undoped silicon oxide (10) over the first surface (2); and (e) annealing the substrate (1) for lowering a peak concentration of boron in the boron doped region (8, 8a) through boron absorption by the undoped silicon oxide. The silicon oxide (10) acts as a boron absorber to obtain the desired concentration of the boron doped region (8).

Method of providing a boron doped region (8, 8a, 8b) in a silicon substrate (1), includes the steps of: (a) depositing a boron doping source (6) over a first surface (2) of the substrate (1); (b) annealing the substrate (1) for diffusing boron from the boron doping source (6) into the first surface (2), thereby yielding a boron doped region; (c) removing the boron doping source (6) from at least part of the first surface (2); (d) depositing undoped silicon oxide (10) over the first surface (2); and (e) annealing the substrate (1) for lowering a peak concentration of boron in the boron doped region (8, 8a) through boron absorption by the undoped silicon oxide. The silicon oxide (10) acts as a boron absorber to obtain the desired concentration of the boron doped region (8).

A multijunction solar cell including an upper first solar subcell having a first band gap and positioned for receiving an incoming light beam; and a second solar subcell disposed below and adjacent to and lattice matched with said upper first solar subcell, and having a second band gap smaller than said first band gap; wherein at least one of the solar subcells has a graded band gap throughout the thickness of at least a portion of its emitter layer and base layer.

A multijunction solar cell including an upper first solar subcell having a first band gap and positioned for receiving an incoming light beam; and a second solar subcell disposed below and adjacent to and lattice matched with said upper first solar subcell, and having a second band gap smaller than said first band gap; wherein at least one of the solar subcells has a graded band gap throughout the thickness of at least a portion of its emitter layer and base layer.

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.