题目：

Stabilized Low-Dimensional Species for Deep-Blue Perovskite Light Emitting Diodes with EQE Approaching 3.4%

作者：

Yu-Hang Zhou¹, Chenyue Wang², Shuai Yuan,^1,* Chen Zou³, Zhenhuang Su², Kai-li Wang¹, Yu Xia¹, Bin Wang¹, Dawei Di³, Zhao-Kui Wang,^1,* and Liang-Sheng Liao¹

单位：

¹Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University, Suzhou 215123, China.

²Shanghai Synchrotron Radiation Facility, Shanghai Advanced Research Institute, Shanghai Institute of Applied Physics Chinese Academy of Sciences, Shanghai 201204, China.

³State Key Laboratory of Modern Optical Instrumentation, College of Optical Science and Engineering, International Research Center for Advanced Photonics, Zhejiang University, Hangzhou 310058, China.

摘要：

Despite recent encouraging developments, achieving efficient blue perovskite light-emitting diodes (PeLEDs) have been widely considered a critical challenge. The efficiency breakthrough only occurred in the sky-blue region, and the device performance of pure-blue and deep-blue PeLEDs lags far behind those of their sky-blue counterparts. To avoid the negative effects associated with dimensionality reduction and excess chloride typically needed to achieve deep-blue emission, here we demonstrate guanidine (GA⁺)-induced deep-blue (~457 nm) perovskite emitters enabling spectrally stable PeLEDs with a record external quantum efficiency (EQE) over 3.41% through a combination of quasi-2D perovskites and halide engineering. Owing to the presence of GA⁺, even a small inclusion of chloride ions is sufficient for generating deep-blue electroluminescence (EL), in clear contrast to the previously reported deep-blue PeLEDs with significant chloride inclusion that negatively affects spectral stability. Based on the carrier dynamics analysis and theoretical calculation, GA⁺ is found to stabilize the low-dimensional species during annealing, retarding the cascade energy transfer and facilitating the deep-blue EL. Our findings open a potential third route to achieve deep-blue PeLEDs beyond the conventional methods of dimensionality reduction and excessive chloride incorporation.

影响因子：

15.419

分区情况：

一区

链接：

https://pubs.acs.org/doi/full/10.1021/jacs.2c07172