Heterojunction Solar Cell with Selective Contacts

A simulated comparative study of silicon solar cells; one utilizing Heterojunction with Intrinsic Thin layer (HIT) technology with the other employing selective contact layers. This paper depicts the possibility that the latter selective contact cell formation could possibly revolutionize the solar cell industry by replacing the former. The selective contact layers use molybdenum oxide (MoO_x, x <; 3) as hole selective layer while lithium fluoride (LiFx is employed as the electron selective layer. Using Automat FOR Simulation of Heterostructures (AFORS-HET), optimization of layer thickness and doping concentration for passivated and unpassivated intrinsic hydrogenated amorphous silicon (a-Si:H) selective contact cell is performed to determine the ideal cell output performance. For both cases of selective contact cell, the effect of carrier lifetime in n-doped bulk crystalline silicon is also observed. Moreover, the impact of using intrinsic hydrogenated amorphous silicon passivation layers in silicon selective contact cell is explained via energy band diagram and the conclusion that these passivation layers are responsible for the increase in open circuit voltage (Voc) and efficiency is established.