n-type silicon solar cells with amorphous/crystalline silicon heterojunction rear emitter

We present the first silicon solar cells processed at Fraunhofer ISE featuring an amorphous/crystalline silicon heterojunction rear emitter and a diffused front surface field. In this work, we focus on the optimization of the silicon heterojunction rear emitter of n-type silicon solar cells with regards to the intrinsic hydrogenated amorphous silicon a-Si:H(i) and boron-doped hydrogenated amorphous silicon a-Si:H(p) layer thickness and the influence of a transparent conducting oxide layer on the rear emitter surface. Efficiencies up to 19.1% (V
_oc
= 687 mV, J
_sc
= 34.9 mA/cm
²
, FF = 79.9%) have been reached for non-textured solar cells on n-type absorbers. Furthermore, we attained an efficiency of 19.8% on textured p-type absorbers featuring an amorphous/crystalline silicon heterojunction rear emitter.