Abstract
We use different temperature parameter to do phosphorus diffusion on multicrystalline silicon wafer. After phosphorus diffusion, we anneal those wafers with different temperatures. Etching off the n-layer just diffused by acid solution, and immerse wafers in dilute KOH solution. Then we discuss the lifetime value on those wafers annealing by different temperature. By this experiment, we get the highest lifetime of those samples. After lifetime measurement we use those wafer as a new p-substrate to diffuse again. By my parameter, those wafers have sheet resistance about 50Ω∕□. Then using plasma- enhanced CVD to deposit 100nm silicon nitride as anti-reflection layer in the national nano device laboratory. By the FTIR system in NDL, we can conclude the Si-H bound exist. And the Si-H bound on wafer surface can repair dangling bound to do passivation. There is hydrogen in the PECVD system when we deposit silicon nitride. After NDL process, we screen print silver and aluminum paste on wafer front and back surface to make electrode. By different time of electrode co-firing, we get different thickness of back surface field. By the FESEM in NDL, we discovered that the best silicon solar cell I make in our lab, the thickness of BSF is about 5μm.