Comparison of high efficiency solar cells on large area n-type and p-type silicon wafers with screen-printed Aluminum-alloyed rear junction

Abstract

Low-cost, high-efficiency, and large area n-type silicon cells can be processed based on the screen printed Aluminum-alloyed rear junction concept. This process uses fabrication techniques which are very close to the current industry-standard screen printed mc-Si cell process. We compare, by experimental tests and modeling, the differences of using n-type wafers and p-type wafers with this process. An independently confirmed record-high efficiency of 17.4% is achieved on n-type floatzone (FZ) silicon wafers (area 140 cm2). On p-type FZ wafers, with the same process 17.6% is obtained, and 16.8% on p-type Cz wafers. Model calculations allow us to identify the potential for further enhancement of the n-type cell efficiency to slightly above 18.0% by improving front surface passivation. We also discuss experimental characteristics of cells produced by this process from n-type multicrystalline wafers.