Abstract
This paper reports a new method to generate stable and high-brightness electroluminescence (EL) by subsequently growing large/small grains at micro/nano scales with the configuration of attaching small grains on the surfaces of large grains in perovskite (MAPbBr3) films by mixing two precursor solutions (PbBr2 + MABr and Pb(Ac)2·3H2O + MABr). Consequently, the small and large grains serve, respectively, as passivation agents and light-emitting centers, enabling self-passivation on the defects located on the surfaces of light-emitting large grains. Furthermore, the light-emitting states become linearly polarized with maximal polarization of 30.8%, demonstrating a very stable light emission (49,119 cd/m2 with EQE = 11.31%) and a lower turn-on bias (1.9 V) than the bandgap (2.25V) in the perovskite LEDs (ITO/PEDOT:PSS/MAPbBr3/TPBi[50 nm]/LiF[0.7 nm]/Ag). Therefore, mixing large/small grains with the configuration of attaching small grains on the surfaces of large grains by mixing two precursor solutions presents a new strategy to develop high-performance perovskite LEDs.
| Original language | English |
|---|---|
| Pages (from-to) | 378-387 |
| Number of pages | 10 |
| Journal | iScience |
| Volume | 19 |
| DOIs | |
| State | Published - Sep 27 2019 |
| Externally published | Yes |
Funding
This research was supported by Air Force Office of Scientific Research (AFOSR) under the Grant no. FA 9550-15-1-0064 , AOARD ( FA2386-15-1-4104 ), the Homeland Security ( DHS-16-DNDO-077-001 ), and National Science Foundation ( NSF-1911659 ). This research was partially conducted at the Center for Nanophase Materials Sciences based on user projects ( CNMS2012-106 , CNMS2012-107 , CNMS-2012-108 ), which is sponsored by Oak Ridge National Laboratory by the Division of Scientific User Facilities , U.S. Department of Energy . The author (J.Q.) was supported by China Scholarship Council (CSC: 201606100126 ).
Keywords
- Materials Characterization
- Optical Materials
- Surface