A method of preparing Group XIII selenide nanoparticles comprises reacting a Group XIII ion source with a selenol compound. The nanoparticles have an M.sub.xSe.sub.y Semiconductor core (where M is In or Ga) and an organic capping ligand attached to the core via a carbon-selenium bond. The selenol provides a source of selenium for incorporation into the semiconductor core and also provides the organic capping ligand. The nanoparticles are particularly suitable for solution-based methods of preparing semiconductor films.

Sodium-containing aluminosilicate and boroaluminosilicate glasses are described herein. The glasses can be used as substrates for photovoltaic devices, for example, thin film photovoltaic devices such as CIGS photovoltaic devices. These glasses can be characterized as having strain points 540 C., thermal expansion coefficient of from 6.5 to 9.5 ppm/ C., as well as liquidus viscosities in excess of 50,000 poise. As such, they are ideally suited for being formed into sheet by the fusion process.

According to the present invention, a CuGa alloy sputtering target which is a sintered body has a composition with 29.5 atom % to 43.0 atom % of Ga and a balance of Cu and inevitable impurities. A CuGa alloy crystal particle in the sintered body has a structure in which phase particles are dispersed in a .sub.1-phase crystal particle. A method for producing the sputtering target includes a step of performing normal pressure sintering by heating a molded body formed of a powder mixture of a pure Cu powder and a CuGa alloy powder in a reducing atmosphere, and a step of cooling the obtained sintered body at a cooling rate of 0.1 C./min to 1.0 C./min, at a temperature having a range of 450 C. to 650 C.

A multilayer stack including a substrate, an active layer, and a tetradymite buffer layer positioned between the substrate and the active layer is disclosed. A method for fabricating a multilayer stack including a substrate, a tetradymite buffer layer and an active layer is also disclosed. Use of such stacks may be in photovoltaics, solar cells, light emitting diodes, and night vision arrays, among other applications.

A photoelectric conversion device includes an electrode layer, a first semiconductor layer located on a main surface of the electrode layer, a plurality of insulating light scattering substances scattered in the first semiconductor layer or scattered at an interface between the first semiconductor layer and the electrode layer, and a second semiconductor layer making a pn junction with the first semiconductor layer on the first semiconductor layer to be located on an opposite side of the electrode layer.

There is provided a quantum dot solar cell having a high optical absorption coefficient. The quantum dot solar cell includes a quantum dot layer 3 including a plurality of quantum dots 1, wherein the quantum dot layer 3 includes a first quantum dot layer 3A having an index /x of 5% or more, wherein x is an average particle size, and is a standard deviation. The quantum dot layer 3 also includes a second quantum dot layer 3B that is provided on the light entrance surface 3b and/or the light exit surface 3c of the first quantum dot layer 3A and has an average particle size and an index /x smaller than those of the first quantum dot layer 3A.

A method for forming a thin film having sulfide single-crystal nanoparticles includes dropping a sulfide precursor solution on the surface of a Group VI absorption layer, and then performing thermal decomposition on the sulfide precursor solution under a predetermined temperature to form a thin film consisting of sulfide single-crystal nanoparticles on the surface of the Group VI absorption layer.

A composition of matter and method of forming copper indium gallium sulfide (CIGS), copper indium gallium selenide (CIGSe), or copper indium gallium telluride thin film via conversion of layer-by-layer (LbL) assembled CuInGa oxide (CIGO) nanoparticles and polyelectrolytes. CIGO nanoparticles are created via a flame-spray pyrolysis method using metal nitrate precursors, subsequently coated with polyallylamine (PAH), and dispersed in aqueous solution. Multilayer films are assembled by alternately dipping a substrate into a solution of either polydopamine (PDA) or polystyrenesulfonate (PSS) and then in the CIGO-PAH dispersion to fabricate films as thick as 1-2 microns. After LbL deposition, films are oxidized to remove polymer and sulfurized, selenized, or tellurinized to convert CIGO to CIGS, CIGSe, or copper indium gallium telluride.

A photoelectric conversion element of an embodiment includes: a back electrode; a heterojunction-type light absorbing layer on the back electrode, containing Cu, selected from Al, In and Ga, and selected from Se and S, and having a chalcopyrite structure; a transparent electrode on the light absorbing layer, wherein aback electrode side-part of the light absorbing layer is of p-type, and a transparent electrode-side part of the light absorbing layer is of n-type, the light absorbing layer has a part with an average crystal grain size of 1,000 nm to 3,000 nm in the vicinity of the back electrode, and the light absorbing layer has apart with an average crystal grain size of at most 500 nm in the vicinity of the transparent electrode or the light absorbing layer has an amorphous part in the vicinity of the transparent electrode.

In order to improve the photoelectric conversion efficiency of a photoelectric conversion device, this photoelectric conversion device is provided with an electrode layer, a first semiconductor layer that is positioned on the electrode layer and contains a polycrystalline semiconductor, and a second semiconductor layer that is positioned on/above the first semiconductor layer and forms a p-n junction with the first semiconductor layer, and an average grain diameter of crystal grains in the first semiconductor layer is larger near the surface on the electrode layer side of the first semiconductor layer than the center of the first semiconductor layer in a thickness direction of the first semiconductor layer. Furthermore, the average grain diameter of the crystal grains in the first semiconductor layer is larger in a surface portion on the second semiconductor layer side of the first semiconductor layer than in the central portion.