Specific contact resistance measurements on C-Si solar cells by novel TLM method

This paper demonstrates a novel device using TLM (transmission line model) method to shorten the operation time of specific contact resistance measurement. It takes about 1 min for each measurement point, and obtaining full-scale solar cell mapping is achievable in an acceptable time. The mappings of emitter sheet resistance and specific contact resistance are obtained on 125×125 mm size solar cells. The comparison of sheet resistance mappings by our TLM device and traditional four-point probe shows that the pattern of the two methods match each other very well, indicating good accuracy of our device. The metallization quality of SE (selective emitter) solar cells by etch-back process is studied. The results in this paper show good potential of our method to detect specific contact resistance on crystalline silicon solar cells.