Using Bulk-like Nanocrystals To Probe Intrinsic Optical Gain Characteristics of Inorganic Lead Halide Perovskites
| Autor: | Emile Drijvers, Jorick Maes, Kai Chen, Pieter Geiregat, Jonathan De Roo, Zeger Hens, Justin M. Hodgkiss |
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| Rok vydání: | 2018 |
| Předmět: |
business.industry
Exciton General Engineering General Physics and Astronomy 02 engineering and technology 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences 0104 chemical sciences Photonic metamaterial Quantum dot Optoelectronics General Materials Science Charge carrier Stimulated emission Thin film 0210 nano-technology business Lasing threshold Biexciton |
| Zdroj: | ACS Nano. 12:10178-10188 |
| ISSN: | 1936-086X 1936-0851 |
| DOI: | 10.1021/acsnano.8b05092 |
| Popis: | Following the introduction of perovskites for photovoltaic solar energy conversion, the use of these materials as a general purpose optoelectronic material for displays, lighting, and lasing has been explored. However, while reports on stimulated emission and lasing by perovskites show great promise, a comprehensive quantification of their optical gain characteristics is lacking. Here, we measure gain coefficients, clarify the gain mechanism, and explore the gain dynamics of colloidal CsPbBr3 nanocrystals by deploying a unique combination of broadband transient absorption and ultrafast fluorescence spectroscopy. Opposite from current literature, we show that optical gain in such nanocrystals is supported by stimulated emission from free carriers, and not from excitons or biexcitons. Importantly, we demonstrate that the concomitant gain coefficients and thresholds agree with literature results reported for perovksite thin films. Finally, we show that, even in the case of fully inorganic lead halide perovskites, a cooling bottleneck hampers the development of net stimulated emission at high excitation density. Based on these results, we propose that bulk-like colloidal nanocrystals in general offer a unique testbed to quantify optical gain of novel photonic materials and in particular for lead halide perovskites. |
| Databáze: | OpenAIRE |
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