Identifying and Reducing Interfacial Losses to Enhance Color-Pure Electroluminescence in Blue-Emitting Perovskite Nanoplatelet Light-Emitting Diodes.
MacManus-Driscoll, Judith L
Urban, Alexander S
ACS energy letters
American Chemical Society (ACS)
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Hoye, R., Lai, M., Anaya, M., Tong, Y., Gałkowski, K., Doherty, T., Li, W., et al. (2019). Identifying and Reducing Interfacial Losses to Enhance Color-Pure Electroluminescence in Blue-Emitting Perovskite Nanoplatelet Light-Emitting Diodes.. ACS energy letters, 4 (5), 1181-1188. https://doi.org/10.1021/acsenergylett.9b00571
Perovskite nanoplatelets (NPls) hold promise for light-emitting applications, having achieved photoluminescence quantum efficiencies approaching unity in the blue wavelength range, where other metal-halide perovskites have typically been ineffective. However, the external quantum efficiencies (EQEs) of blue-emitting NPl light-emitting diodes (LEDs) have only reached 0.12%. In this work, we show that NPl LEDs are primarily limited by a poor electronic interface between the emitter and hole-injector. We show that the NPls have remarkably deep ionization potentials (≥6.5 eV), leading to large barriers for hole injection, as well as substantial non-radiative decay at the NPl/hole-injector interface. We find that an effective way to reduce these non-radiative losses is by using poly(triarylamine) interlayers. Using these, we increase the EQE of our blue LEDs emitting at 464 nm wavelength to 0.3%, as well as increase the EQE of our sky-blue-emitting LEDs to 0.55%. Our work also identifies the key challenges for further efficiency increases.
Royal Academy of Engineering (RAEng) (RF\201718\17101)
European Commission Horizon 2020 (H2020) ERC (756962)
European Commission Horizon 2020 (H2020) Marie Sk?odowska-Curie actions (841386)
External DOI: https://doi.org/10.1021/acsenergylett.9b00571
This record's URL: https://www.repository.cam.ac.uk/handle/1810/292261
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