Abstract: Because the present J-V measurement systems for solar cells were complex， expensive and inconvenient to use，a new system which can auto-calibrate the xenon lamp irradiance and automatically measure several devices simultaneously was developed． The system consists of a computer，a testing program，a Keithley 2 400 source meter，a 500 W xenon lamp and its power supply，an automatic switching and measuring circuit for multiple devices，a xenon lamp operating time measuring circuit，a photocurrent measuring circuit composed of a reference photodiode and an irradiance calibration circuit． PC testing software was written in Visual Basic． The light power of the Xenon lamp was monitored using the photocurrent of a reference photodiode illuminated by the
lamp and calibrated to standard 100 mW /cm2 AM 1． 5 solar irradiance before every J-V measurement via modulating the output voltage of the Xenon lamp power supply using a microprocessor． The photocurrent of the custom solar cells under different bias voltage was measured using a Keithley 2400 source meter and a multi-sample automatic measurement circuit． The J-V curves were plotted and the device parameters such as efficiency were calculated by the testing software． The system proposed is cost-effective，highly automatic and fulfills the requirements of solar cells J-V testing．

Key words: solar cell, J-V characteristic, measurement system, multi-sample automatic measurement, auto-calibration of light irradiance