Incorporating a monolayer of WS2 via interface engineering enhances the overall physical properties of a FAPbI3 perovskite based heterostructure. FAPbI3/WS2/TiO2/ITO and FAPbI3/TiO2/ITO heterostructures were analyzed by UV-Vis spectroscopy, X-ray diffraction, scanning electron microscopy and atomic force microscopy. The configuration with WS2 interlayer presents higher absorption in the visible region with a bandgap of {\aprox} 1.44 eV. WS2 also enhances the deposition process of FAPbI3, resulting in the formation of pure photoactive α-phase without the non-photoactive δ-phase nor residual plumbates. The incorporation of the monolayer improves the crystalline structure of the FAPbI3, promoting a preferential growth in the [100] direction. The smooth surface of WS2 favors a homogeneous morphology and an increase of the grain size to ~4.5 μm, the largest reported for similar structures. Furthermore, the work function obtained lets us propose an enhance an adequate energy band alignment between FAPbI3 and the n-type layers for the electron flux to the cathode. These findings strongly suggest that the interfacial coupling of FAPbI3/WS2 could be a promising candidate in photovoltaic applications.
Cite
@article{arxiv.2404.03802,
title = {WS$_2$ Monolayer Integration in a FAPbI$_3$-based Heterostructure},
author = {Jorge Luis Miró-Zárate and Felipe Cervantes-Sodi and Milton Carlos Elias-Espinosa and Skarleth García-Trujillo and Carolina Janani Diliegros-Godines},
journal= {arXiv preprint arXiv:2404.03802},
year = {2024}
}