Perovskites with narrow quantum-wells distribution and thermally activated energy funneling for sky-blue light-emitting diodes

Authors：Sun, Guanwei; Qiu, Weidong; Li, Jiayu; Zhang, Shuai; Chen, Zijian; Liu, Denghui; Shen, Chenyang; Wen, Tao; Liu, Zhe; Pu, Junrong; Yang, Zhihai; Yang, Guo-xi; Li, Ming-De^*; Su, Shi-Jian^*

Source：Chemical Engineering Journal, 2023, 475: 146360.

DOI：10.1016/j.cej.2023.146360

• Perovskite light-emitting diodes
• Thermally activated energy funneling
• Narrow quantum-wells regulation
• Sky-blue

Reduced dimensional perovskite light-emitting diodes have undergone rapid development in recent years, leading to improved device efficiency surpassing their three-dimensional counterparts. However, its fundamental carrier characteristics have not been thoroughly investigated. In this study, A-site cation formamidinium (FA) and co-spacer cation isobutylamine (iBA) are incorporated into reduced-dimensional perovskite PEA2Cs3Pb4Br10Cl3 (where PEA is phenylethylammonium), and a more concentrated quantum-wells distribution is observed due to the utilization of co-spacer cations and the interaction between spacer cations and FA+, facilitating enhanced energy funneling process. Additionally, thermally activated energy funneling process is firstly reported which contribute to the thermally activated long-lived delayed photoluminescence. A longer decay signal at emission center can be observed in transient absorption spectrum of the PEA2i-BA2Cs2FAPb4Br12Cl3 perovskite film due to the more sufficient energy transfer. Owing to the efficient carrier utilization and reduced defect states, sky-blue perovskite light-emitting diodes are successfully fabricated with peak external quantum efficiency of 12.7 % and high luminance of 4513 cd m- 2.

• Institution
  汕头大学