Interdigitated back-contacted silicon heterojunction solar cells using semi-industrial processing equipment

Interdigitated back-contacted a-Si:H/c-Si heterojunction solar cells were made using two different approaches for patterning the a-Si:H layers: screen-printing in combination with wet chemical etching and in-situ mechanical masking. Processing was restricted to semi-industrial, low cost processing equipment on 6" wafers, cut back after processing into nine smaller cells by laser. After active layer patterning, implied V_OC values of over 700 mV were measured for both approaches and the best J_SC and V_OC values on cell level were 39.7 mA/cm² and 697 mV, respectively. Efficiencies over 21% are expected, when some metallization issues at the rear are solved.