NOVELTY - An artificial amorphous semiconductor material having a controlled bandgap and mobility comprises crystalline semiconductor material quantum dots uniformly distributed and regularly spaced in three dimensions through a matrix of dielectric material or thin layers of dielectric materials. The bandgap and mobility of the material are determined by selecting the material parameters.    USE - For photovoltaic junctions in a photovoltaic cell (claimed) e.g. solar cell.    ADVANTAGE - A variable bandgap can be obtained within the same materials systems. This materials system is consistent with the exceptional stability and durability of silicon wafer-based product as well as that based on crystalline silicon films on glass.    DETAILED DESCRIPTION - An artificial amorphous semiconductor material having a controlled bandgap and mobility comprises crystalline semiconductor material quantum dots (23) uniformly distributed and regularly spaced in three dimensions through a matrix of dielectric material or thin layers of dielectric materials. The bandgap and mobility of the material are determined by selecting the material parameters including the size of the quantum dots, the composition of the matrix and the semiconductor material of the quantum dots.    INDEPENDENT CLAIMS are also included for:    (a) a method of forming an artificial amorphous semiconductor material having a controlled bandgap and mobility comprising forming layers of dielectric material including a compound of a semiconducting material, wherein alternating layers are layers of stoichiometric dielectric material (21) and layers of semiconductor-rich dielectric material (22); and heating the layers of dielectric material to cause quantum dots to form in the semiconductor-rich layers of dielectric material, whereby they are uniformly distributed and regularly spaced in three dimensions through the dielectric material;    (b) a photovoltaic junction comprising an n-type region of artificial amorphous material adjacent a p-type region of artificial amorphous material forming a junction, wherein the n-type and p-type artificial amorphous materials are integrally formed as a matrix of dielectric material in which crystalline semiconductor material quantum dots are regularly dispersed and the n-type and p-type regions are respectively doped with n-type and p-type dopant atoms;    (c) an artificial amorphous material photovoltaic cell comprising photovoltaic junctions stacked in tandem; and    (d) a method of forming an artificial amorphous semiconductor material photovoltaic cell comprising forming alternating layers of stoichiometric dielectric material and layers of semiconductor-rich dielectric material; doping regions of the layers of dielectric material with p-type and n-type dopants either simultaneously with their formation or subsequently; and heating the layers of dielectric material to cause quantum dots to form in the semiconductor-rich layers.    DESCRIPTION OF DRAWING(S) - The figure shows the alternating stoichiometric and silicon-rich layers of a superlattice structure after high temperature treatment.    Stoichiometric dielectric material layers (21)    Semiconductor-rich dielectric material layers (22)    Quantum dots (23)