High efficiency multicrystalline silicon solar cells: Potential of n-type doping

Abstract

By quantifying the role of dopants, impurities and crystal structure, we present guidelines for the fabrication of highly efficient multicrystalline (mc) silicon solar cells. Processed mc n-type wafers feature higher charge carrier diffusion lengths and thus a significantly larger efficiency potential compared with identically produced mc p-type wafers. Still, metal impurities limit the charge carrier lifetime in mc n-type wafers. We identify the main metal impurities in mc n-type silicon and quantify the resulting recombination losses. Attributing the main losses to precipitates and decorated crystal defects, the optimal efficiency potential of mc silicon is exploited by combining n-type highperformance multicrystalline silicon (HPM-Si) with a high efficiency cell concept featuring a full area passivated rear contact (TOPCon). The record cell features an efficiency of 19.6%, which is the highest efficiency reported for an mc n-type silicon solar cell. By reducing series resistance losses and improving the optics of the front surface, efficiencies of 21-22% should be attainable on n-type HPM-Si TOPCon solar cells.

Finding 10% hidden electricity in crystalline Si solar cells using PDMS coating and three‐dimensional cell arrays

“…Over the past few decades, the crystalline silicon (Si) solar cell industry has matured and photovoltaics is now considered a key aspect of renewable energy production. 1,2 This development has led to the continuous improvement of crystalline Si solar cells from back surface field structures (BSF) to passivated emitter and rear contact (PERC), [3][4][5] tunneling oxide passivated contact (TOPCon), [6][7][8][9] interdigitated back contact (IBC), [10][11][12][13] and heterojunction intrinsic thin layer (HIT) solar cells [14][15][16] as well as enhanced light trapping structures such as surface texturing 1,2,17,18 and cello structured grids. 19 With this development, the efficiency of crystalline Si solar cells has been increased to 26.7% at the lab-scale by HIT-IBC cells.…”