Enhanced ultraviolet electroluminescence and spectral narrowing from ZnO quantum dots/GaN heterojunction diodes by using high-k HfO{sub 2} electron blocking layer

Journal Article · Mon Aug 11 04:00:00 EDT 2014 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.4893280· OSTI ID:22318024

Mo, Xiaoming; Long, Hao; Wang, Haoning; Chen, Zhao; Wan, Jiawei; Liu, Yuping; Fang, Guojia ^[1]; Li, Songzhan ^[1]; Feng, Yamin ^[2]; Ouyang, Yifang ^[3]

---

1. Key Lab of Artificial Micro- and Nano-Structures of Ministry of Education, School of Physics and Technology, Wuhan University, Wuhan 430072 (China)
2. Department of Physics, Institute of Nanoscience and Nanotechnology, Central China Normal University, Wuhan 430079 (China)
3. College of Physical Science and Technology, Guangxi University, Nanning, Guangxi 530004 (China)

We demonstrated the capability of realizing enhanced ZnO-related UV emissions by using the low-cost and solution-processable ZnO quantum dots (QDs) with the help of a high-k HfO{sub 2} electron blocking layer (EBL) for the ZnO QDs/p-GaN light-emitting diodes (LEDs). Full-width at half maximum of the LED devices was greatly decreased from ∼110 to ∼54 nm, and recombinations related to nonradiative centers were significantly suppressed with inserting HfO{sub 2} EBL. The electroluminescence of the ZnO QDs/HfO{sub 2}/p-GaN LEDs demonstrated an interesting spectral narrowing effect with increasing HfO{sub 2} thickness. The Gaussian fitting revealed that the great enhancement of the Zn{sub i}-related emission at ∼414 nm whereas the deep suppression of the interfacial recombination at ∼477 nm should be the main reason for the spectral narrowing effect.

• OSTI ID: 22318024
• Journal Information: Applied Physics Letters, Journal Name: Applied Physics Letters Journal Issue: 6 Vol. 105; ISSN APPLAB; ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
DEPLETION LAYER
ELECTROLUMINESCENCE
ELECTRONS
GALLIUM NITRIDES
HAFNIUM OXIDES
HETEROJUNCTIONS
LIGHT EMITTING DIODES
LINE NARROWING
QUANTUM DOTS
ULTRAVIOLET RADIATION
ZINC OXIDES