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)
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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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