Abstract
Chalcogenide perovskites have emerged as a new class of optoelectronic materials, especially for photovoltaic applications, but fundamental properties and applications of chalcogenide perovskites remain limited due to the lack of high-quality thin films. We report direct epitaxial thin film growth of BaZrS3, a prototypical chalcogenide, by pulsed laser deposition. X-ray diffraction studies show that the films are strongly textured out-of-plane and have a clear in-plane epitaxial relationship with the substrate. Electron microscopy studies confirm the presence of epitaxy for the first few layers of the film at the interface, even though away from the interface, the films are polycrystalline with many extended defects, suggesting the potential for further improvement in growth. X-ray reflectivity and atomic force microscopy show smooth film surfaces and interfaces between the substrate and the film. The films show strong light absorption near the band edge and photoluminescence in the visible region, validating BaZrS3as a suitable candidate for ultrathin front absorbers in tandem solar cells. The photodetector devices show fast and efficient photo response with the highest ON/OFF ratio reported for BaZrS3films thus far. Our study opens up opportunities to use high quality thin films of chalcogenide perovskites to probe fundamental physical phenomena in thin films and heterostructures and also in photovoltaic and optoelectronic applications.
| Original language | English |
|---|---|
| Pages (from-to) | 7457-7464 |
| Number of pages | 8 |
| Journal | Chemistry of Materials |
| Volume | 33 |
| Issue number | 18 |
| DOIs | |
| State | Published - Sep 28 2021 |
| Externally published | Yes |
Funding
This work was supported by the Army Research Office under award numbers W911NF-19-1-0137 and W911NF-21-1-0327, the National Science Foundation of the United States under grant numbers DMR-2122070 and 2122071, and the USC Provost New Strategic Directions for Research Award. R.M. and A.S.T. acknowledge support from the National Science Foundation through grant number DMR-1806147. The work of HPT processing at Oregon State University was supported by the National Science Foundation of the United States under grant no. DMR-1810343. TRPL experiments were conducted at the Center for Integrated Nanotechnologies, an Office of Science User Facility operated for the U.S. Department of Energy (DOE) Office of Science and supported by DOE BES, QIS Infrastructure Development Project “Deterministic Placement and Integration of Quantum Defects”. The authors gratefully acknowledge the use of facilities at Dr. Stephen Cronin’s Lab, John O’Brien Nanofabrication Laboratory and Core Center for Excellence in Nano Imaging at University of Southern California for the results reported in this manuscript. M.S. acknowledges technical assistance from Jeremy Intrator. STEM sample preparation was conducted at the Center for Nanophase Materials Sciences at Oak Ridge National Laboratory (ORNL), which is a Department of Energy (DOE) Office of Science User Facility, through a user project (A.S.T. and R.M.). Microscopy work performed at ORNL was supported by the U.S. DOE, Office of Science, Basic Energy Sciences Materials Science and Engineering Division (BES-MSED). We acknowledge helpful discussions with Dr. Rafael Jaramillo of the Massachusetts Institute of Technology, whose research group recently achieved similar epitaxial BZS film growth using molecular beam epitaxy.
| Funders | Funder number |
|---|---|
| Basic Energy Sciences Materials Science and Engineering Division | |
| National Science Foundation | DMR-2122070, 2122071 |
| U.S. Department of Energy | |
| Directorate for Mathematical and Physical Sciences | 1810343, 1806147 |
| Army Research Office | W911NF-19-1-0137, W911NF-21-1-0327 |
| Office of Science | |
| Basic Energy Sciences | |
| University of South Carolina | DMR-1806147, DMR-1810343 |
