In this paper, we have studied the effect of high-resistanceSnO2buffer layers, deposited by low-pressure chemical-vapor deposition, on CdS/CdTe device performance. Our results indicate that when CdS/CdTe devices have a very thin layer of CdS or no CdS at all, thei-SnO2buffer layer helps to increase device efficiency. When the CdS layer is thicker than 600 Å, the device performance is dominated by CdS thickness, not thei-SnO2layer. If a very thin CdS layer is to be used to enhance device performance, we conclude that a betterSnO2buffer layer is needed. ©1999 American Institute of Physics.