Device simulation of low cost HTM free perovskite solar cell based on TiO_2 electron transport layer

摘要

The perovskite solar cells (PSCs) have great attention now a days because of the material used in these devices are hybrid organic-inorganic materials with ABX_3 structure which are good light harvesters, eco-friendly and low-cost materials known as 'perovskites. However, their commercialization is limited due to its low stability, costly HTL and electrode materials, low durability and so on. In this study, we modeled a HTM free PSC with device structure Glass/FTO/TiO_2/CH_3NH_3PbI_(3-x)Cl_x/carbon where TiO_2 is employed as an electron transport layer (ETL) and Chloride (Cl) doped CH_3NH_3PbI_3 i.e. CH_3NH_3PbI_(3-x)Cl_x as a light absorber layer because of its enhanced thermal stability and film quality and low cost carbon as back contact. The effect of thickness and band gap of perovskite layer have been studied. It is found that the appropriate thickness and band gap of perovskite were around 500nm and 1.5eV respectively. Also, the high work function (≥ 5eV) back contact material and its good alignment are favorable for solar cell parameters in our device structure. We found that a power conversion efficiency (PCE) over 14.27% can be obtained under the moderate simulation conditions. These results will provide a path leading towards development of low cost and high efficient solar cell.