Hard and soft Lewis-base behavior for efficient and stable CsPbBr3 perovskite light-emitting diodes
Sun Changjiu,
Wei Junli,
Zhao Jian,
Jiang Yuanzhi,
Wang Yilong,
Hu Haiqing,
Wang Xin,
Zhang Yongqin,
Yuan Mingjian
Affiliations
Sun Changjiu
Key Laboratory of Rubber-Plastics Ministry of Education/Shandong Provincial Key Laboratory of Rubber-Plastics, Qingdao University of Science & Technology, 266042, Qingdao, P. R. China
Wei Junli
Key Laboratory of Adv. Energy Mater. Chemistry (Ministry of Education), Renewable Energy Conversion and Storage Center (RECAST), College of Chemistry, Nankai University, 300071, Tianjin, P. R. China
Zhao Jian
Key Laboratory of Rubber-Plastics Ministry of Education/Shandong Provincial Key Laboratory of Rubber-Plastics, Qingdao University of Science & Technology, 266042, Qingdao, P. R. China
Jiang Yuanzhi
Key Laboratory of Adv. Energy Mater. Chemistry (Ministry of Education), Renewable Energy Conversion and Storage Center (RECAST), College of Chemistry, Nankai University, 300071, Tianjin, P. R. China
Wang Yilong
Key Laboratory of Rubber-Plastics Ministry of Education/Shandong Provincial Key Laboratory of Rubber-Plastics, Qingdao University of Science & Technology, 266042, Qingdao, P. R. China
Hu Haiqing
Key Laboratory of Rubber-Plastics Ministry of Education/Shandong Provincial Key Laboratory of Rubber-Plastics, Qingdao University of Science & Technology, 266042, Qingdao, P. R. China
Wang Xin
Key Laboratory of Rubber-Plastics Ministry of Education/Shandong Provincial Key Laboratory of Rubber-Plastics, Qingdao University of Science & Technology, 266042, Qingdao, P. R. China
Zhang Yongqin
College of Chemical Engineering, Qingdao University of Science & Technology, 266042, Qingdao, P. R. China
Yuan Mingjian
Key Laboratory of Adv. Energy Mater. Chemistry (Ministry of Education), Renewable Energy Conversion and Storage Center (RECAST), College of Chemistry, Nankai University, 300071, Tianjin, P. R. China
All-inorganic CsPbBr3 perovskite is an attractive emission material for high-stability perovskite light-emitting diodes (PeLEDs), due to the high thermal and chemical stability. However, the external quantum efficiencies (EQEs) of CsPbBr3 based PeLEDs are still far behind their organic–inorganic congeners. Massive defect states on the surface of CsPbBr3 perovskite grains should be the main reason. Lewis base additives have been widely used to passivate surface defects. However, systematic investigations which relate to improving the passivation effect via rational molecule design are still lacking. Here, we demonstrate that the CsPbBr3 film’s optical and electrical properties can be significantly boosted by tailoring the hardness–softness of the Lewis base additives. Three carboxylate Lewis bases with different tail groups are selected to in-situ passivate CsPbBr3 perovskite films. Our research indicates that 4-(trifluoromethyl) benzoate acid anion (TBA−) with the powerful electron-withdrawing group trifluoromethyl and benzene ring possesses the softest COO− bonding head. TBA− thus acts as a soft Lewis base and possesses a robust combination with unsaturated lead atoms caused by halogen vacancies. Based on this, the all-inorganic CsPbBr3 PeLEDs with a maximum EQE up to 16.75% and a half-lifetime over 129 h at an initial brightness of 100 cd m−2 is thus delivered.
