Ultra-Thin 2D MoTe2 for Electron Transport Material Application in Perovskite Solar Cell: A Theoretical Approach

Abstract

With rapid progress in power conversion efficiencies, perovskite solar cells (PSCs) have shown great potential as next-generation low- cost, efficient solar cell devices. Ultra-thin pure and Brdoped MoTe₂ monolayer materials are promising candidates for alternative  electron transport material in perovskite solar cell applications. The electronic, and optical properties of these materials were calculated  using projector augmented plane wave (PAW) based on popular density-functional theory (DFT). These properties were calculated using  Pardew-BurkeErnzerhof generalized gradient approximation (PBE-GGA). The band structure for the considered materials has been  determined using full relativistic spin-orbital coupling (SOC). Our results indicate that pure and Br-doped 2D-MoTe₂ were n-type  semiconductors and had direct band gap energies of 1.01 and 1.21 eV respectively. The optical properties of the materials such as relative  dielectric constant, transmission and reflectivity are presented. Using these properties, the 1-D solar cell capacitance simulator  (SCAPS-1D) software was used to design solar cells based on monolayer pure and Br-doped MoTe2 as an electron transport layer (ETL).  The maximum efficiencies of these cells are 13.121%, and 24.016% with VOC of 1.067 V and 1.186 V, JSC of 21.678 mA/cm² and 25.251 mA/ cm2 , and FF of 56.720% and 80.139% were realized with the pure and Br-doped ETLs respectively. The performance of our solar cells is  comparable to traditional Si-based solar cells. The results show how monolayer pure and Br-doped MoTe₂ can serve as a suitable ETL  material for perovskite solar cells.