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Perovskite Light-emitting Diodes with Tunable Emission


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Type

Thesis

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Authors

Lai, May Ling 

Abstract

Solid-state lightings are becoming the popular choice for lightings due to its higher efficiency, improved colour rendering index and the flexibility of various size and shape. Halide perovskite has tunable colour emission, low disorder and is solution processable making it one of a popular choice as emitters. This thesis demonstrates the versatility of using halide perovskite material in light-emitting diodes. We demonstrate the first working perovskite light-emitting diode at room temperature by introducing thin layer of perovskite emitter which is crucial to confine the inherent free carriers in the material. We show that the 3D lead-halide bulk perovskite is bandgap tunable with emission in the green and red visible spectrum. Light-emitting diodes in the visible spectrum are common however near-infrared emission is a rarity. Lead is a heavy metal which is known for its toxicity. We tackled the issue of toxicity by replacing with tin and demonstrate tunable emission in the near-infrared region. Bulk perovskites have large binding energy which makes it difficult to confine the charges and form radiative recombination which is crucial for emission and efficiency of the device. We move into lower dimensionality perovskites by utilising all-inorganic perovskite nanoplatelets and show emission in the blue region.

Description

Date

2018-04-30

Advisors

Friend, Richard Henry

Keywords

perovskite, light-emitting diodes, nanoplatelet, tunable emission, halide perovskite

Qualification

Doctor of Philosophy (PhD)

Awarding Institution

University of Cambridge

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