Scientists suggest unique bilayer structure for crystalline silicon solar cells

• Researchers from the Shanghai Advanced Research Institute (SARI) of the Chinese Academy of Sciences have proposed an unique "bilayer" structure composing of various change metal oxide (TMO) thin films in crystalline silicon (c-Si) solar cells in order to boost the cells' effectiveness.

The researchers combined NiOx and MoOx films right into a bilayer framework that removes "hole carriers" from c-Si a lot more efficiently than single-layer films can. The results were released in Cell Reports Physical Science.

"Hole carriers" bring a positive charge. Together with electrons, which have contrary polarity, they were produced after c-Si absorbs sun light. By extracting positive holes as well as negative electrons from c-Si to outside circuits, the sun light is converted to usable power - this is what a c-Si solar cell does. "Drawing out" service providers from c-Si is critical as well as they can be recognized by carrier-selective calls (CSCs) such as TMO films.

CSCs play a crucial role in improving the power conversion performance (PCE) of c-Si cells. Existing single-layer, thin TMO films such as MoOx or NiOx can not efficiently remove the wanted carriers-mainly holes, thus resulting in c-Si solar cells with sub-par efficiency.

In a NiOx/MoOx bilayer framework, however, MoOx can induce band bending at the interface, which agrees with for hole service provider extraction. Additionally, NiOx assists to block unwanted electron providers. This is confirmed by both band placement simulation and minority carrier life time dimensions.

Taking advantages of these functions, the researchers reported an exceptional PCE of 21.31% in c-Si solar cells utilizing NiOx/MoOx bilayers.

Moreover, forming an added ultra-thin SiOx layer on the silicon surface area can better reduce loss pathways such as recombination, etc.

Therefore, making use of an NiOx/SiOx/MoOx framework can better increase the gadget's PCE to 21.60%. This is the highest reported performance of any c-Si solar cell utilizing MoOx-based hole-selective calls rather than an expensive a-Si: H passivation layer, according to the scientists.

This research highlights an appealing and also robust approach to utilizing bilayers as reliable frameworks for drawing out hole carriers. It acts as an inspiring guide for dealing with obstacles in the field of passivating call c-Si solar cells.

This work was sustained by the National Natural Science Foundation of China, the Natural Science Foundation of Shanghai, as well as the Shanxi Science and Technology Department, among others.