Harvesting Delayed Fluorescence in Perovskite Nanocrystals Using Spin-Forbidden Mn d States
| Autor: | Margherita Zavelani-Rossi, K R Pradeep, Chandrabhas Narayana, Shobhana Narasimhan, Anur Yadav, Kushagra Gahlot, Giulio Cerullo, Andrea Camellini, Debdipto Acharya, Ranjani Viswanatha, Priyanka Jain |
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| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: |
Materials science
Photoluminescence Energy Engineering and Power Technology Quantum yield 02 engineering and technology Electron 010402 general chemistry 01 natural sciences Molecular physics symbols.namesake Mn doping Materials Chemistry Perovskite (structure) Renewable Energy Sustainability and the Environment 021001 nanoscience & nanotechnology Perovskite Nanocrystals 0104 chemical sciences Fuel Technology Chemistry (miscellaneous) Molecular vibration symbols ultrafast charge dynamics Density functional theory Quantum efficiency fluorescence 0210 nano-technology Raman spectroscopy |
| Zdroj: | ACS energy letters 5 (2020): 353–359. doi:10.1021/acsenergylett.9b02399 info:cnr-pdr/source/autori:Pradeep, K. R.; Acharya, Debdipto; Jain, Priyanka; Gahlot, Kushagra; Yadav, Anur; Camellini, Andrea; Zavelani-Rossi, Margherita; Cerullo, Giulio; Narayana, Chandrabhas; Narasimhan, Shobhana; Viswanatha, Ranjani/titolo:Harvesting Delayed Fluorescence in Perovskite Nanocrystals Using Spin-Forbidden Mn d States/doi:10.1021%2Facsenergylett.9b02399/rivista:ACS energy letters/anno:2020/pagina_da:353/pagina_a:359/intervallo_pagine:353–359/volume:5 |
| DOI: | 10.1021/acsenergylett.9b02399 |
| Popis: | Optoelectronic devices based on all-inorganic perovskite systems are an energy-efficient source of lighting due to their high photoluminescence quantum yield (QY). However, dominant surface trapping continues to plague the field, despite their high defect tolerance, as evidenced by the several-fold improvements in the external quantum efficiency of perovskite nanocrystals (NCs) upon appropriate surface passivation or physical confinement between high-band-gap materials. Here, we introduce the concept of drip-feeding of photoexcited electrons from an impurity-induced spin-forbidden state to address this major shortcoming. An increased and delayed (about several milliseconds) excitonic QY, Raman spectroscopy demonstrating specific vibrational modes of the PbX6 octahedra, and density functional theory establish the electron back-transfer, signifying an efficient recombination. We term this electron back-transfer from Mn2+ to the host conduction band in this prototypical example of Mn-doped CsPbX3 (X = Cl, Br) NCs through vibrational coupling as vibrationally assisted delayed fluorescence (VADF). |
| Databáze: | OpenAIRE |
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