Techniques for achieving band gap grading in CZTS/Se absorber materials are provided. In one aspect, a method for creating band gap grading in a CZTS/Se absorber layer includes the steps of: providing a reservoir material containing Si or Ge; forming the CZTS/Se absorber layer on the reservoir material; and annealing the reservoir material and the CZTS/Se absorber layer under conditions sufficient to diffuse Si or Ge atoms from the reservoir material into the CZTS/Se absorber layer with a concentration gradient to create band gap grading in the CZTS/Se absorber layer. A photovoltaic device and method of forming the photovoltaic device are also provided.

A photovoltaic or light detecting device is provided that includes a periodic array of dome or dome-like protrusions at the light impingement surface and three forms of reflector/back electrode at the device back. The beneficial interaction between an appropriately designed top protrusion array and these reflector/electrode back contacts (R/EBCs) serve (1) to refract the incoming light thereby providing photons with an advantageous larger momentum component parallel to the plane of the back (R/EBC) contact and (2) to provide optical impedance matching for the short wavelength incoming light. The reflector/back electrode operates as a back light reflector and counter electrode to the periodic array of dome or dome-like structures. A substrate supports the reflector/back electrode.

Disclosed is a photovoltaic device comprising a substrate composed of an oriented polycrystalline zinc oxide sintered body in a plate shape, a photovoltaic layer provided on the substrate, and an electrode provided on the photovoltaic layer. According to the present invention, a photovoltaic device having high photoelectric conversion efficiency can be inexpensively provided.

An optoelectronic device with a multi-layer contact is described. The optoelectronic device can include a n-type semiconductor layer having a surface. A mesa can be located over a first portion of the surface of the n-type semiconductor layer and have a mesa boundary. A n-type contact region can be located over a second portion of the surface of the n-type semiconductor contact layer entirely distinct from the first portion, and be at least partially defined by the mesa boundary. A first n-type metallic contact layer can be located over at least a portion of the n-type contact region in proximity of the mesa boundary, where the first n-type metallic contact layer forms an ohmic contact with the n-type semiconductor layer. A second n-type metallic contact layer can be located over a second portion of the n-type contact region, where the second n-type metallic contact layer is formed of a reflective metallic material.

In one aspect, semiconductor structures are described herein. A semiconductor structure, in some implementations, comprises a first semiconductor layer having a first bandgap and a first lattice constant and a second semiconductor layer having a second bandgap and a second lattice constant. The second lattice constant is lower than the first lattice constant. Additionally, a transparent metamorphic buffer layer is disposed between the first semiconductor layer and the second semiconductor layer. The buffer layer has a constant or substantially constant bandgap and a varying lattice constant. The varying lattice constant is matched to the first lattice constant adjacent the first semiconductor layer and matched to the second lattice constant adjacent the second semiconductor layer. The buffer layer comprises a first portion comprising Al.sub.yGa.sub.zIn.sub.(1-y-z)As and a second portion comprising Ga.sub.xIn.sub.(1-x)P. The first portion is adjacent the first semiconductor layer and the second portion is adjacent the second semiconductor layer.

The invention provides a laminate of an inorganic layer, a resin layer, and a coupling agent treatment layer interposed therebetween, which different delamination strengths between the inorganic layer and the resin layer to form a prescribed pattern. The invention also provides a production method comprising (1) treating an inorganic layer with a coupling agent; (2) performing a patterning process to form strong adhesion sections and easily separated sections; and (3) forming a resin layer by drying and heat-treating a coated solution layer obtained by coating a resin solution or a resin precursor solution onto the surface of the inorganic layer that was treated with a coupling agent and then patterned.

A high efficiency configuration for a string of solar cells comprises series-connected solar cells arranged in an overlapping shingle pattern. Front and back surface metallization patterns may provide further increases in efficiency.

A process of forming and the resulting nano-pitted metal substrate that serves both as patterns to grow nanostructured materials and as current collectors for the resulting nanostructured material is disclosed herein. The nano-pitted substrate can be fabricated from any suitable conductive material that allows nanostructured electrodes to be grown directly on the substrate.

A hybrid vapor phase-solution phase CZT(S,Se) growth technique is provided. In one aspect, a method of forming a kesterite absorber material on a substrate includes the steps of: depositing a layer of a first kesterite material on the substrate using a vapor phase deposition process, wherein the first kesterite material includes Cu, Zn, Sn, and at least one of S and Se; annealing the first kesterite material to crystallize the first kesterite material; and depositing a layer of a second kesterite material on a side of the first kesterite material opposite the substrate using a solution phase deposition process, wherein the second kesterite material includes Cu, Zn, Sn, and at least one of S and Se, wherein the first kesterite material and the second kesterite material form a multi-layer stack of the absorber material on the substrate. A photovoltaic device and method of formation thereof are also provided.

A multi-junction photovoltaic cell includes a substrate and a back contact layer formed on the substrate. A low bandgap Group IB-IIIB-VIB.sub.2 material solar absorber layer is formed on the back contact layer. A heterojunction partner layer is formed on the low bandgap solar absorber layer, to help form the bottom cell junction, and the heterojunction partner layer includes at least one layer of a high resistivity material having a resistivity of at least 100 ohms-centimeter. The high resistivity material has the formula (Zn and/or Mg)(S, Se, O, and/or OH). A conductive interconnect layer is formed above the heterojunction partner layer, and at least one additional single-junction photovoltaic cell is formed on the conductive interconnect layer, as a top cell. The top cell may have an amorphous Silicon or p-type Cadmium Selenide solar absorber layer. Cadmium Selenide may be converted from n-type to p-type with a chloride doping process.