The disclosure provides a solar cell design featuring p-or-n type GaAs with alternating p-n junction regions on the back-surface of the cell, opposite incident solar irradiance. Various layers of p-or-n type GaAs are interfaced together to collect charge carriers, and a thin layer of AlGaAs is applied to the front and back surfaces to prevent recombination of charge carriers. In some embodiments, the layered an doped structure generally provides an AlGaAs window layer of about 20 nm doped to about 4×(10.sup.18) cm.sup.−3, a GaAs absorption layer of about 2000 nm doped to about 4×(10.sup.17) cm.sup.−3, a GaAs emitter layer of about 150 nm and doped to 1×(10.sup.18) cm.sup.−3, an AlGaAs heterojunction layer of about 40 nm doped to about 3×(10.sup.18) cm.sup.−3, and a GaAs emitter-contact layer of about 20 nm doped to about 1×(10.sup.19) cm.sup.−3. Additionally, AlGaAs BSF layer and GaAs BSF-contact layers each have a depth of about 20 nm and are doped to about 4×(10.sup.18) cm.sup.−3 and 1×(10.sup.19) cm.sup.−3 respectively. The emitter layer, heterojunction layer, and emitter-contact layer are doped to a conductivity type opposite the absorption layer.

A method of forming a multijunction solar cell that includes an InGaAs buffer layer and an InGaAlAs grading interlayer disposed below, and adjacent to, the InGaAs buffer layer. The grading interlayer achieves a transition in lattice constant from one solar subcell to another adjacent solar subcell.

A method of forming a multijunction solar cell that includes an InGaAs buffer layer and an InGaAlAs grading interlayer disposed below, and adjacent to, the InGaAs buffer layer. The grading interlayer achieves a transition in lattice constant from one solar subcell to another adjacent solar subcell.

The present disclosure provides a fuel production method and a fuel production apparatus which efficiently convert solar light energy into a fuel. The fuel production apparatus of the present disclosure includes a laminate, an electrolytic bath, and a support tool or a proton permeable membrane. The laminate includes a photoelectromotive layer having a p-n junction structure, a cathode electrode, an anode electrode and a side surface insulating layer, and the photoelectromotive layer includes a semiconductor layer that absorbs light in a near-infrared region with a wavelength of 900 nm or more. In the fuel production apparatus, an underwater optical path length is set to an optimum design value, so that even light in a near-infrared region with a wavelength of 900 nm or more is sufficiently utilized to efficiently convert light energy into at least one fuel selected from hydrogen, carbon monoxide, formic acid, methane, ethylene, methanol, ethanol, isopropanol, allyl alcohol, acetaldehyde and propionaldehyde through a reduction reaction on the cathode electrode.

System and method of providing a photovoltaic (PV) cell having a cushion layer to alleviate stress impact between a front metal contact and a thin film PV layer. A cushion layer is disposed between an extraction electrode and a photovoltaic (PV) surface. The cushion layer is made of a nonconductive material and has a plurality of vias filled with a conductive material to provide electrical continuity between the bus bar and the PV layer. The cushion layer may be made of a flexible material preferably with rigidity that matches the substrate. Thus, the cushion layer can effectively protect the PV layer from physical damage due to tactile contact with the front metal contact.

System and method of providing a photovoltaic (PV) cell having a cushion layer to alleviate stress impact between a front metal contact and a thin film PV layer. A cushion layer is disposed between an extraction electrode and a photovoltaic (PV) surface. The cushion layer is made of a nonconductive material and has a plurality of vias filled with a conductive material to provide electrical continuity between the bus bar and the PV layer. The cushion layer may be made of a flexible material preferably with rigidity that matches the substrate. Thus, the cushion layer can effectively protect the PV layer from physical damage due to tactile contact with the front metal contact.

A photovoltaic device and a method of forming a contact stack of the photovoltaic device are disclosed. The photovoltaic device may include a first layer deposited on a semiconductor layer including a compound semiconductor material. The photovoltaic device may also include a dopant layer comprising tin (Sn) deposited on the first layer. The photovoltaic device may further include a conductive layer deposited or provided over the dopant layer to form a contact stack with the first layer and the dopant layer.

A photovoltaic device and a method of forming a contact stack of the photovoltaic device are disclosed. The photovoltaic device may include a first layer deposited on a semiconductor layer including a compound semiconductor material. The photovoltaic device may also include a dopant layer comprising tin (Sn) deposited on the first layer. The photovoltaic device may further include a conductive layer deposited or provided over the dopant layer to form a contact stack with the first layer and the dopant layer.

The present application discloses a multi-junction tandem laser photovoltaic cell, comprising a photovoltaic cell stack and a bottom electrode and a top electrode electrically connected to a bottom and a top of the photovoltaic cell stack, respectively, wherein the photovoltaic cell stack comprises stacked N AlGaAs PN-junction sub-cells, and adjacent sub-cells are connected in series via a tunneling junction, in which N≥2. The AlGaAs PN-junction sub-cells use an AlGaAs absorbing layer. The present application further discloses a method of making the multi-junction tandem laser photovoltaic cell. The present application uses AlGaAs as the absorbing layer of the multi-junction tandem cell to convert laser energy, which can effectively increase the open circuit voltage of the photovoltaic cell, thereby significantly improving the conversion efficiency of the photovoltaic cell.

The present application discloses a multi-junction tandem laser photovoltaic cell, comprising a photovoltaic cell stack and a bottom electrode and a top electrode electrically connected to a bottom and a top of the photovoltaic cell stack, respectively, wherein the photovoltaic cell stack comprises stacked N AlGaAs PN-junction sub-cells, and adjacent sub-cells are connected in series via a tunneling junction, in which N≥2. The AlGaAs PN-junction sub-cells use an AlGaAs absorbing layer. The present application further discloses a method of making the multi-junction tandem laser photovoltaic cell. The present application uses AlGaAs as the absorbing layer of the multi-junction tandem cell to convert laser energy, which can effectively increase the open circuit voltage of the photovoltaic cell, thereby significantly improving the conversion efficiency of the photovoltaic cell.