Impact of organic overlayers on a-Si:H/c-Si surface potential
byJohannes P Seif, Bjoern Niesen, Andrea Tomasi, Christophe Ballif, Stefaan De Wolf
Seif, Johannes P., Bjoern Niesen, Andrea Tomasi, Christophe Ballif, and Stefaan De Wolf. "Impact of organic overlayers on a-Si: H/c-Si surface potential." Applied Physics Letters 110, no. 15 (2017): 151601.
Bilayers of intrinsic and doped hydrogenated amorphous silicon, deposited on crystalline silicon (c-Si) surfaces, simultaneously provide contact passivationand carrier collection in silicon heterojunction solar cells. Recently, we have shown that the presence of overlaying transparent conductive oxides can significantly affect the c-Si surface potential induced by these amorphous silicon stacks. Specifically, deposition on the hole-collecting bilayers can result in an undesired weakening of contact passivation, thereby lowering the achievable fill factor in a finished device. We test here a variety of organic semiconductors of different doping levels, overlaying hydrogenated amorphous silicon layers and silicon-based hole collectors, to mitigate this effect. We find that these materials enhance the c-Si surface potential, leading to increased implied fill factors. This opens opportunities for improved device performance.