Femtosecond Excitonic Relaxation Dynamics of Perovskite on Mesoporous Films of Al2O3 and NiO Nanoparticles |
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| Authors: | Hung‐Yu Hsu Chi‐Yung Wang Amir Fathi Jia‐Wei Shiu Chih‐Chun Chung Po‐Shen Shen Prof. Dr. Tzung‐Fang Guo Prof. Dr. Peter Chen Prof. Dr. Yuan‐Pern Lee Prof. Dr. Eric Wei‐Guang Diau |
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| Affiliation: | 1. Department of Applied Chemistry and Institute of Molecular Science, National Chiao Tung University, Hsinchu 300 (Taiwan);2. Department of Photonics and Advanced Optoelectronic Technology Center, National Cheng Kung University, Tainan 701 (Taiwan) |
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| Abstract: | The excitonic relaxation dynamics of perovskite adsorbed on mesoporous thin films of Al2O3 and NiO upon excitation at 450 nm were investigated with femtosecond optical gating of photoluminescence (PL) via up‐conversion. The temporal profiles of emission observed in spectral region 670–810 nm were described satisfactorily with a composite consecutive kinetic model and three transient components representing one hot and two cold excitonic relaxations. All observed relaxation dynamics depend on the emission wavelength, showing a systematic time–amplitude correlation for all three components. When the NiO film was employed, we observed an extent of relaxation proceeding through the non‐emissive surface state larger than through the direct electronic relaxation channel, which quenches the PL intensity more effectively than on the Al2O3 film. We conclude that perovskite is an effective hole carrier in a p‐type electrode for NiO‐based perovskite solar cells showing great performance. |
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| Keywords: | exciton relaxation femtochemistry kinetics perovskite solar cells |
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