Thickness optimization and the effect of different hole transport materials on methylammonium tin iodide (CH3NH3SnI3)-based perovskite solar cell

In the era of modern photovoltaic technology, perovskite solar cell is one of the most intriguing topics for its cost-effective fabrication step and high absorbance. Tin-based and lead-based perovskites are the two popular compounds of perovskite cell fabrication. Generally, the power conversion efficiency (PCE) and the stability of tin-based perovskite are much less than the lead-based perovskite. However, the toxicity of lead demotivates usage of this material as the absorber layer. To remove this problem, an alternative solution of tin-based perovskite with a configuration of glass substrate/FTO/TiO2/CH3NH3SnI3/HTM/back contact is briefly investigated in this paper. The thickness optimization effects of perovskite and hole transport material (HTM) on overall PCE is also observed. Moreover, the impact of the hole transport layer (HTL) with its characteristic parameters such as bandgap and hole mobilities on the PCE with five different HTMs, i.e., Spiro-OMeTAD, CuI, Cu2O, NiO, and PEDOT:PSS, are studied through the proposed numerical model. Finally, it is found that the inorganic HTMs, i.e., CuI and Cu2O, show better PCE than the organic materials Spiro-OMeTAD and PEDOT:PSS. The highest PCE as an HTM is reordered for CuI with the PCE of 21.0%.