Experiments on the modification of the bi-layer structure in CdS/CuInSe2 devices

Preliminary studies of modifications of the standard bilayer approach to CdS/CuInSe₂ device fabrication are reported. It is shown that the incorporation of CuIn_1-xGa_xSe₂ and CuIn_1-xAl_xSe₂ quaternary alloys into the space-charge region substantially enhances open-circuit voltage. Short-circuit current losses are minimized when thin discrete layers of these alloys are placed at the selenide/sulfide interface. Placing CuGaSe₂ at the back contact of the device enhances the near-infrared spectral response. The application of cyanide- and chromium-based chemical treatments improves overall device performance through the removal of bulk secondary phases and reduction of interface recombination centers.