The effect of H passivation in ribbon multi-crystalline Si (mc-Si) wafers from SiNx:H anti-reflecting layer was studied by using the simultaneous rapid thermal annealing of Al back-contact and SiNx anti-reflection coating on the front (RTP-Al/SiNx). Scanning room-temperature photoluminescence spectroscopy revealed a strong inhomogeneity in the increase of minority carrier lifetime caused by the H defect passivation in mc-Si. Experimental evidence was presented that RTP-Al/SiNx processing led to strong lifetime enhancement caused by H defect passivation in low-lifetime regions of mc-Si wafers. Additional details on the hydrogenation mechanism were revealed in the course of a dehydrogenation study. The H out-diffusion exhibited a different rate or activation energy for the high- and low-lifetime regions of the wafers.

Defect Passivation in Multicrystalline Silicon for Solar Cells. I.Tarasov, S.Ostapenko, K.Nakayashiki, A.Rohatgi: Applied Physics Letters, 2004, 85[19], 4346-8