Bifacial heterojunction silicon solar cells by hot-wire CVD with open-circuit voltages exceeding 600 mV

Double-sided (bifacial) heterojunction silicon solar cells have been fabricated by Hot-Wire CVD on both p- and n-type crystalline silicon substrates. In these devices, doped microcrystalline silicon layers are combined with thin intrinsic amorphous silicon buffers. Such heterojunction with intrinsic thin layer concept is applied to obtain both the low temperature deposited emitter and back surface field contact. Especially remarkable is the performance of the solar cell fabricated on p-type c-Si. This device yields a total area (1.4 cm2) conversion efficiency of 13.3%, with an open-circuit voltage of 619 mV, short-circuit current density of 29.0 mA cm− 2 and fill factor of 74.1%. The substrate temperature is kept below 200 °C during the whole fabrication process.