| Autor: |
Ekanayaka TK; Department of Physics and Astronomy, University of Nebraska-Lincoln, Lincoln, NE 68588, USA., Richmond D; Department of Physics, State University of New York-Oswego, Oswego, NY 13126, USA., McCormick M; Department of Chemistry, University of Nebraska-Lincoln, Lincoln, NE 68588-0304, USA., Nandyala SR; Department of Electrical and Computer Engineering, University of Wyoming, Laramie, WY 82071, USA., Helfrich HC; Department of Physics, Oklahoma State University, Stillwater, OK 74078, USA.; Department of Physics, Pittsburg State University, Pittsburg, KS 66762, USA., Sinitskii A; Department of Chemistry, University of Nebraska-Lincoln, Lincoln, NE 68588-0304, USA., Pikal JM; Department of Electrical and Computer Engineering, University of Wyoming, Laramie, WY 82071, USA., Ilie CC; Department of Physics, State University of New York-Oswego, Oswego, NY 13126, USA., Dowben PA; Department of Physics and Astronomy, University of Nebraska-Lincoln, Lincoln, NE 68588, USA., Yost AJ; Department of Physics, Oklahoma State University, Stillwater, OK 74078, USA.; Oklahoma Photovoltaic Research Institute, Oklahoma State University, Stillwater, OK 74078, USA. |
| Abstrakt: |
The anion exchange of the halides, Br and I, is demonstrated through the direct mixing of two pure perovskite quantum dot solutions, CsPbBr 3 and CsPbI 3 , and is shown to be both facile and result in a completely alloyed single phase mixed halide perovskite. Anion exchange is also observed in an interlayer printing method utilizing the pure, unalloyed perovskite solutions and a commercial inkjet printer. The halide exchange was confirmed by optical absorption spectroscopy, photoluminescent spectroscopy, X-ray diffraction, and X-ray photoemission spectroscopy characterization and indicates that alloying is thermodynamically favorable, while the formation of a clustered alloy is not favored. Additionally, a surface-to-bulk photoemission core level transition is observed for the Cs 4d photoemission feature, which indicates that the electronic structure of the surface is different from the bulk. Time resolved photoluminescence spectroscopy indicates the presence of multiple excitonic decay features, which is argued to originate from states residing at surface and bulk environments. |
