Multi-quantum barriers (MQBs) has been introduced into a single quantum well (SQW) solar cell to prevent the photo-generated electrons in the quantum well from leaking into the p-side, and is therefore intended for a new method to reduce the dark current and thereby improving the overall spectral response of the quantum well solar cell. Here we report on the performances of the MQB by dark current and photoluminescence measurement. It is found that the leakage possibility of the photo-generated electrons in the SQW into p-side and thus the dark current is suppressed for solar cell with MQB compared with that without MQB. (C) 2005 Springer Science + Business Media, Inc.