| Autor: |
Liu, Albert, Almeida, Diogo B., Bonato, Luiz G., Nagamine, Gabriel, Zagonel, Luiz F., Nogueira, Ana F., Padilha, Lazaro A., Cundiff, Steven T. |
| Rok vydání: |
2020 |
| Předmět: |
|
| Druh dokumentu: |
Working Paper |
| Popis: |
Advances in opto-electronics require the development of materials with novel and engineered characteristics. A class of materials that has garnered tremendous interest is metal-halide perovskites, stimulated by meteoric increases in photovoltaic efficiencies of perovskite solar cells. In addition, recent advances have applied perovskite nanocrystals (NCs) in light-emitting devices. It was discovered recently that, for cesium lead-halide perovskite NCs, their unusually efficient light-emission may be due to a unique excitonic fine-structure composed of three bright triplet states that minimally interact with a proximal dark singlet state. To study this fine-structure without isolating single NCs, we use multi-dimensional coherent spectroscopy at cryogenic temperatures to reveal coherences involving triplet states of a CsPbI$_3$ NC ensemble. Picosecond timescale dephasing times are measured for both triplet and inter-triplet coherences, from which we infer a unique exciton fine-structure level-ordering comprised of a dark state energetically positioned within the bright triplet manifold. |
| Databáze: |
arXiv |
| Externí odkaz: |
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