| Autor: |
Andaji-Garmaroudi, Z, Abdi-Jalebi, M, Kosasih, FU, Doherty, T, Macpherson, S, Bowman, AR, Man, GJ, Cappel, UB, Rensmo, H, Ducati, C, Friend, RH, Stranks, SD |
| Přispěvatelé: |
Man, GJ [0000-0003-2932-7018], Stranks, SD [0000-0002-8303-7292], Apollo - University of Cambridge Repository |
| Rok vydání: |
2020 |
| Předmět: |
|
| DOI: |
10.17863/cam.59284 |
| Popis: |
Halide perovskites have attracted substantial interest for their potential as disruptive display and lighting technologies. However, perovskite light-emitting diodes (PeLEDs) are still hindered by poor operational stability. A fundamental understanding of the degradation processes is lacking but will be key to mitigating these pathways. Here, we use a combination of in operando and ex-situ measurements to monitor the performance degradation of (Cs0.06FA0.79MA0.15)Pb(I0.85Br0.15)3 PeLEDs over time. Through device, nanoscale cross-sectional chemical mapping, and optical spectroscopy measurements, we reveal that the degraded performance arises from an irreversible accumulation of bromide content at one interface, which leads to barriers to injection of charge carriers and thus increased non-radiative recombination. We impede this ionic segregation by passivating the perovskite films with potassium halides, which immobilizes the excess halide species. The passivated PeLEDs show enhanced external quantum efficiency (EQE) from 0.5 to 4.5% and, importantly, show significantly enhanced stability, with minimal performance roll-off even at high current densities (> 200 mA/cm2). The decay half-life for the devices under continuous operation at peak EQE increases from |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
|
