Voltage-Controlled Reversible Modulation of Colloidal Quantum Dot Thin Film Photoluminescence

Fuente: arXiv
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Autores principales: Xie, Sihan, Zhu, Han, Li, Melissa, Bulović, Vladimir
Formato: Preprint
Publicado: 2020
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author Xie, Sihan
Zhu, Han
Li, Melissa
Bulović, Vladimir
author_facet Xie, Sihan
Zhu, Han
Li, Melissa
Bulović, Vladimir
contents Active modulation of quantum dot thin film photoluminescence (PL) has far-reaching potential applications in biomedical and optoelectronic systems, but challenges remain in achieving large PL modulation depth and fast temporal response. Here we report an efficient voltage-controlled optical down-converter by optically exciting a colloidal quantum dot thin film within a quantum dot light-emitting diode (QD-LED) under reverse bias. Utilizing field-induced luminescence quenching, we show that a large electric field can strongly modify carrier dynamics in this nanostructured device, resulting in stable and reversible photoluminescence quenching. The device exhibits photoluminescence reduction of up to 99.5%, corresponding to a contrast ratio of 200:1, under the applied electric field of 3 MV/cm, with a 300 nanosecond response time. Using excitation wavelength dependent and transient PL spectroscopy, we further show that the high degree of quenching is achieved by a synergistic interplay of quantum-confined Stark effect (QCSE) and field-induced exciton dissociation.
format Preprint
id arxiv_https___arxiv_org_abs_2008_05375
institution arXiv
publishDate 2020
record_format arxiv
spellingShingle Voltage-Controlled Reversible Modulation of Colloidal Quantum Dot Thin Film Photoluminescence
Xie, Sihan
Zhu, Han
Li, Melissa
Bulović, Vladimir
Applied Physics
Active modulation of quantum dot thin film photoluminescence (PL) has far-reaching potential applications in biomedical and optoelectronic systems, but challenges remain in achieving large PL modulation depth and fast temporal response. Here we report an efficient voltage-controlled optical down-converter by optically exciting a colloidal quantum dot thin film within a quantum dot light-emitting diode (QD-LED) under reverse bias. Utilizing field-induced luminescence quenching, we show that a large electric field can strongly modify carrier dynamics in this nanostructured device, resulting in stable and reversible photoluminescence quenching. The device exhibits photoluminescence reduction of up to 99.5%, corresponding to a contrast ratio of 200:1, under the applied electric field of 3 MV/cm, with a 300 nanosecond response time. Using excitation wavelength dependent and transient PL spectroscopy, we further show that the high degree of quenching is achieved by a synergistic interplay of quantum-confined Stark effect (QCSE) and field-induced exciton dissociation.
title Voltage-Controlled Reversible Modulation of Colloidal Quantum Dot Thin Film Photoluminescence
topic Applied Physics
url https://arxiv.org/abs/2008.05375