Theoretical modelling of high-efficiency perovskite solar cells and reduction of internal heat generation using hot-electron extraction

Perovskite single crystals have received enormous attention in recent years. This is, perhaps, due to their simplistic synthesis and excellent optoelectronic properties including the long carrier diffusion length, high carrier mobility, low trap density, and tuneable absorption edge ranging from ultra-violet to near-infrared. These distinguishing features offer numerous potential applications in energy-related fields like solar cells, photodetectors, lasers, etc. Efficiency enhancement and stability, in general, are the main challenges to obtaining better solar cells. One of the main reasons for the early degradation of solar cells is heat generation due to high energy electrons and holes in the conduction and valance bands. In this study, the authors try to introduce the concept of selective energy contacts in perovskite solar cells. Also, they investigate how this concept affects the power conversion efficiency (enhancement) and heat generation due to hot electrons and holes (reduction) scattering in the conduction and valance bands. Both efficiency enhancement and reduction in heat generation have been calculated in this study. Thus, for mathematical modeling of the anticipated idea, the Methylammonium lead halide (CH 3 NH 3 PbI 3 ) material is used in a PIN structure for a single-junction solar cell. Also, for the proposed structure, analytical modeling was introduced and it is shown that the efficiency of a single contact cell is around 25%, and after applying the second contact, the efficiency was increased to 35%. Finally, due to the reduction of heat loss in the structure, the stability of perovskite material is significantly increased.