Kevin Ye1,Jack Van Sambeek1,Ida Sadeghi1,Rafael Jaramillo1
Massachusetts Institute of Technology1
Kevin Ye1,Jack Van Sambeek1,Ida Sadeghi1,Rafael Jaramillo1
Massachusetts Institute of Technology1
Chalcogenides perovskites are candidate materials for solar energy conversion technologies due to their promising optoelectronic properties and chemical stability [1–3]. The prototype chalcogenide perovskite BaZrS<sub>3</sub> is a semiconductor with direct band gap of <i>E</i><sub>g</sub> = 1.9 eV, and Shockley-Read-Hall recombination lifetime exceeding 50 ns demonstrated in single crystals; we have also recently demonstrated that <i>E</i><sub>g</sub> can be reduced continuously to 1.4 eV through alloying with Se.<br/>Here we present results of making and testing BaZrS<sub>3</sub> thin-film solar cells in a substrate architecture, as long-established for CIGS technologies. We deposit BaZrS<sub>3</sub> thin films on Mo metal rear contact layers by reactive physical vapor deposition using H<sub>2</sub>S. The deposition is similar to our demonstrated synthesis by molecular beam epitaxy (MBE) [4], but BaZrS<sub>3</sub> can also be grown as polycrystalline, non-epitaxial, single-phase thin films. We deposit <i>n</i>-type CdS contacts by chemical bath deposition, followed by sputtering ZnO and ITO layers in typical dot-cell geometry. We report results of completed solar cell device tests (I-V and EQE), and quantitative loss analysis based on measured optical and electrical properties of isolated thin-films and device semifabricates. We conclude with an outlook for improving device performance and comments on future manufacturability of chalcogenide perovskite solar cells.<br/>1. R. Jaramillo and J. Ravichandran, "In praise and in search of highly-polarizable semiconductors: Technological promise and discovery strategies," APL Mater. <b>7</b>(10), 100902 (2019).<br/>2. S. Niu, D. Sarkar, K. Williams, Y. Zhou, Y. Li, E. Bianco, H. Huyan, S. B. Cronin, M. E. McConney, R. Haiges, R. Jaramillo, D. J. Singh, W. A. Tisdale, R. Kapadia, and J. Ravichandran, "Optimal Bandgap in a 2D Ruddlesden–Popper Perovskite Chalcogenide for Single-Junction Solar Cells," Chem. Mater. <b>30</b>(15), 4882–4886 (2018).<br/>3. S. Niu, J. Milam-Guerrero, Y. Zhou, K. Ye, B. Zhao, B. C. Melot, and J. Ravichandran, "Thermal stability study of transition metal perovskite sulfides," J. Mater. Res. <b>33</b>(24), 4135–4143 (2018).<br/>4. I. Sadeghi, K. Ye, M. Xu, Y. Li, J. M. LeBeau, and R. Jaramillo, "Making BaZrS <sub>3</sub> Chalcogenide Perovskite Thin Films by Molecular Beam Epitaxy," Adv. Funct. Mater. 2105563 (2021).