The effect of chemical surface treatments on non-native /Bi2O3/ GaAs metal-insulator-semiconductor solar cells

GaAs metal-insulator-semiconductor solar cells with a physically deposited Bi2O3 interfacial layer have been investigated. The deposition techniques used in the study were electron beam and thermal evaporation. The cells fabricated with interfacial layers of Bi2O3 showed a substantial improvement in open-circuit voltage over cells made without the physically deposited oxide layer. An etch has been used which yields an irregular 'textured' surface. Cells employing this surface had a higher short-circuit current than those made with smooth, polished surfaces. The open-circuit voltages of these textured cells were lower than those with smooth surfaces. Calculations of the dependence of open-circuit voltage on pinhole density are in agreement with these results since a rough surface has a greater probability of pinholes.