Interfacial interactions and optoelectronic properties of Cs2AgInCl6/ J-TMDs heterojunctions for photovoltaic applications

The photoelectric performance of double perovskites is relatively poor compared to traditional perovskite materials, constructing heterojunctions to improve its optoelectronic properties is an effective strategy for designing high-performance double perovskite optoelectronic applications. In this study, we undertook a comprehensive investigation into the electronic and optical characteristics of Cs2AgInCl6/janus transition-metal dichalcogenides (J-TMDs) heterojunctions based on density functional theory (DFT) calculations. Our findings reveal that the construction of van der Waals heterojunctions is only feasible when the Cs-Cl (001) surface of the double perovskite comes into contact with J-TMDs. The nature of the heterojunction formed between Cs2AgInCl6 Cs-Cl surface and J-TMDs (MXY) relies on the disparity in atomic numbers between X and Y, thereby influencing the charge transfer and interface interaction. Moreover, the Cs-Cl/WXY heterojunction exhibits the most promising features for optoelectronic applications due to its lower effective mass and lower exciton binding energy. The optical absorption coefficients of Cs-Cl/J-TMDs heterojunctions surpass those of corresponding Cs2AgInCl6 monolayers, signifying their potential utility in solar cells. Additionally, we computed the power conversion efficiency (PCE) of Cs2AgInCl6/MXY heterojunctions and found that the Cs-Cl/WSeTe-Se heterojunction demonstrates the highest PCE (11.25 %) among all Cs2AgInCl6/MXY heterojunctions, positioning it as a promising material for photovoltaic applications. These results provide valuable insights into the design and optimization of Cs2AgInCl6/MXY heterojunctions for the development of high-performance optoelectronic devices.