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Amplified Spontaneous Emission Based on 2D Ruddlesden–Popper Perovskites
Author(s) -
Li Meili,
Gao Qinggang,
Liu Peng,
Liao Qing,
Zhang Haihua,
Yao Jiannian,
Hu Wenping,
Wu Yishi,
Fu Hongbing
Publication year - 2018
Publication title -
advanced functional materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.069
H-Index - 322
eISSN - 1616-3028
pISSN - 1616-301X
DOI - 10.1002/adfm.201707006
Subject(s) - materials science , optoelectronics , perovskite (structure) , light emitting diode , band gap , population inversion , exciton , thin film , diode , spontaneous emission , amplified spontaneous emission , laser , nanotechnology , optics , condensed matter physics , crystallography , chemistry , physics
2D Ruddlesden–Popper perovskites (RPPs) are a class of quantum‐well (QW) materials, composed of layered perovskite QWs encapsulated between two hydrophobic organic layers. Different from widely investigated 3D‐perovskites with free carriers at room temperature, 2D‐RPPs exhibit strongly bound electron–hole pairs (excitons) for high‐performance solar cells and light emitting diodes (LEDs). Herein, it is reported that self‐organized multiple QWs in 2D‐RPP thin films naturally form an energy cascade, which enables an ultrafast energy transfer process from higher energy‐bandgap QWs to lower energy‐bandgap QWs. Therefore, photoexcitations are concentrated on lower‐bandgap QWs, facilitating the build‐up of population inversion. Room‐temperature amplified spontaneous emission (ASE) from 2D‐RPP thin films is achieved at dramatically low thresholds, with gain coefficients as high as >300 cm −1 , and stoichiometrically tunable ASE wavelengths from visible to near‐infrared spectral range (530–810 nm). In view of the high efficiency reported for LEDs, these solution‐processed 2D‐RPP thin films may hold the key to realize electrically driven lasers.