Abstract
We developed an easy and accurate method for incident photons-to-electrons conversion efficiency（IPCE）measurement of space-charge-limited (SCL) photovoltaic devices. An extra white light bias is usually introduced in IPCE system to obtain the correct IPCE of SCL devices since the relationship between current and incident light intensity is nonlinear. However, the validity and nessecity of the extra light bias requires further proof. Therefore, we used blue, green and orange light-emitting diode (LED) to verify the validity and nessecity. The validity and necessity of white light bias were examined in both conventional and inverted organic solar cell. The white light is proven be valid as light bias correctly and necessary in the IPCE measurement system to obtain the accurate IPCE of SCL photovoltaic devices from the experiment results. SCL effect also appears to be more significant under stronger light illumination.