Premium
Potassium Doping to Enhance Green Photoemission of Light‐Emitting Diodes Based on CsPbBr 3 Perovskite Nanocrystals
Author(s) -
Hoang Minh Tam,
Pannu Amandeep Singh,
Tang Cheng,
Yang Yang,
Pham Ngoc Duy,
Gui Ke,
Wang Xiaoxiang,
Yambem Soniya,
Sonar Prashant,
Du Aijun,
Wang Hongxia
Publication year - 2020
Publication title -
advanced optical materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.89
H-Index - 91
ISSN - 2195-1071
DOI - 10.1002/adom.202000742
Subject(s) - materials science , perovskite (structure) , optoelectronics , dopant , doping , light emitting diode , diode , quantum efficiency , halide , nanocrystal , nanotechnology , chemical engineering , inorganic chemistry , chemistry , engineering
Metal halide perovskite nanocrystals (PeNCs) are emerging as one of the most promising materials for optoelectrical devices such as light‐emitting diode (LED) owing to their tunable band gaps, high color purity, and tolerance to defects. Nevertheless, the materials have not yet demonstrated their full potential in practical applications due to the poor stability of PeNCs and their unsatisfactory performance in devices. In this research, LED devices based on CsPbBr 3 NCs are successfully demonstrated as an active light‐emitting layer with enhanced efficiency via potassium doping. The study of the effect of potassium dopant on physicochemical properties of inorganic CsPbBr 3 PeNCs shows that potassium cations (K + ) remain in the crystal structure of perovskite compound as interstitial defects, which results in better coverage of surface ligands on the PeNCs and improved energy band alignment with adjacent electron injection layer (2,2′,2′‐(1,3,5‐benzinetriyl)‐tris(1‐phenyl‐1‐ H ‐benzimidazole)) and hole injection layer (poly(3,4‐ethylenedioxythiophene) polystyrene sulfonate) in an LED. As a consequence, the green LED with the K‐doped CsPbBr 3 PeNCs shows luminance up to 5759 cd m ‐2 and external quantum efficiency (EQE) of 5.6%, which is superior to the pristine device without K‐doping (luminance: 4579 cd m ‐2 , EQE: 4.8%).