| 학회 |
한국화학공학회 |
| 학술대회 |
2021년 봄 (04/21 ~ 04/23, 부산 BEXCO) |
| 권호 |
27권 1호, p.923 |
| 발표분야 |
재료 |
| 제목 |
Discrete Emissive States of Quantum Dot Electroluminescence Device |
| 초록 |
Core/shell colloidal quantum dot (QDs) are one of emerging materials in electroluminescence (EL) device for future information displays owing to facile band gap (Eg) tunability, high color purity and quantum efficiency. However, the biphasic morphology of QDs isolated by wide Eg shells makes emissive states in individual QDs discrete and unable to exchange carriers injected. We unveil the discrete nature of QDs in EL devices by manipulating carrier injection events. Adopting hole transport layers with varied ionization energy enable holes to be injected to the entire QD ensembles, but electrons to be introduced to specific QDs. The red-shifted and asymmetric EL spectra represent selective injection of electrons into narrow Eg QDs with smaller electron injection barriers. The spectrally-resolved, Eg-dependent EL intensity – current reveals that the wide Eg QDs become optically dark due to excess holes while the narrow Eg QDs accepts electrons and holes in balanced manner. Our finding suggests the general mechanistic picture on QLEDs operation that is governed by the nature of individual QDs, not by averaged characteristics of ensembled QDs. |
| 저자 |
이현준1, 정병국2, 배완기2, 이도창1, 임재훈2
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| 소속 |
1한국과학기술원(KAIST), 2성균관대 |
| 키워드 |
화공재료 |
| E-Mail |
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| 원문파일 |
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