Fabrication and Optoelectronic Properties of a Transparent    ZnO Homostructural Light-Emitting Diode

Guo, Xinli; Choi, Jae-Hyoung; Tabata, Hitoshi; Kawai, Tomoji

doi:10.1143/jjap.40.l177

Cited by 250 publications

(102 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Even so, this intensity ratio is significantly better than those of the p-i-n junctions and metal-insulator-semiconductor ͑MIS͒ junctions demonstrated previously. 17,24 The performance of our ZnO LEDs should be further improved by using transparent electrodes and double heterostructures such as ZnMgO / ZnO / ZnMgO or ZnO / ZnCdO / ZnO.…”

mentioning

confidence: 99%

ZnO light-emitting diode grown by plasma-assisted metal organic chemical vapor deposition

Zeng

et al. 2006

Applied Physics Letters

259

102

View full text Add to dashboard Cite

We report a breakthrough in fabricating ZnO homojunction light-emitting diode by metal organic chemical vapor deposition. Using NO plasma, we are able to grow p-type ZnO thin films on n-type bulk ZnO substrates. The as-grown films on glass substrates show hole concentration of 10 16 -10 17 cm −3 and mobility of 1 -10 cm 2 V −1 s −1 . Room-temperature photoluminescence spectra reveal nitrogen-related emissions. A typical ZnO homojunction shows rectifying behavior with a turn-on voltage of about 2.3 V. Electroluminescence at room temperature has been demonstrated with band-to-band emission at I = 40 mA and defect-related emissions in the blue-yellow spectrum range.

show abstract

mentioning

confidence: 99%

ZnO light-emitting diode grown by plasma-assisted metal organic chemical vapor deposition

Zeng

et al. 2006

Applied Physics Letters

259

102

View full text Add to dashboard Cite

show abstract

“…Recently, ZnO has attracted renewed interest owing to applications in transparent electrodes, utilizing its high n-type conductivity and optical transparency (E g = 3.44 eV [3]). In addition, optoelectronic applications such as light-emitting diodes and ultraviolet lasers have been extensively explored using its p-n and p-i-n homojunctions [4][5][6][7][8] and p-n heterojunctions [9,10]. The quantum Hall effect has been observed recently in a high-mobility two-dimensional electron gas formed at ZnO/Mg x Zn 1−x O heterojunctions [11,12].…”

Section: Introductionmentioning

confidence: 99%

Point defects in ZnO: an approach from first principles

Oba

Choi

Togo

et al. 2011

Science and Technology of Advanced Materials

321

222

View full text Add to dashboard Cite

Recent first-principles studies of point defects in ZnO are reviewed with a focus on native defects. Key properties of defects, such as formation energies, donor and acceptor levels, optical transition energies, migration energies and atomic and electronic structure, have been evaluated using various approaches including the local density approximation (LDA) and generalized gradient approximation (GGA) to DFT, LDA + U/GGA + U , hybrid Hartree-Fock density functionals, sX and GW approximation. Results significantly depend on the approximation to exchange correlation, the simulation models for defects and the post-processes to correct shortcomings of the approximation and models. The choice of a proper approach is, therefore, crucial for reliable theoretical predictions. First-principles studies have provided an insight into the energetics and atomic and electronic structures of native point defects and impurities and defect-induced properties of ZnO. Native defects that are relevant to the n-type conductivity and the non-stoichiometry toward the O-deficient side in reduced ZnO have been debated. It is suggested that the O vacancy is responsible for the non-stoichiometry because of its low formation energy under O-poor chemical potential conditions. However, the O vacancy is a very deep donor and cannot be a major source of carrier electrons. The Zn interstitial and anti-site are shallow donors, but these defects are unlikely to form at a high concentration in n-type ZnO under thermal equilibrium. Therefore, the n-type conductivity is attributed to other sources such as residual impurities including H impurities with several atomic configurations, a metastable shallow donor state of the O vacancy, and defect complexes involving the Zn interstitial. Among the native acceptor-type defects, the Zn vacancy is dominant. It is a deep acceptor and cannot produce a high concentration of holes. The O interstitial and anti-site are high in formation energy and/or are electrically inactive and, hence, are unlikely to play essential roles in electrical properties. Overall defect energetics suggests a preference for the native donor-type defects over acceptor-type defects in ZnO. The O vacancy, Zn interstitial and Zn anti-site have very low formation energies when the Fermi level is low. Therefore, these defects are expected to be sources of a strong hole compensation in p-type ZnO. For the n-type doping, the compensation of carrier electrons by the native acceptor-type defects can be mostly suppressed when O-poor chemical potential conditions, i.e. low O partial pressure conditions, are chosen during crystal growth and/or doping.

show abstract

“…Most of the recent research on ZnO has concentrated on epitaxial growth of thin films and their properties, and device production was the driving motivation in many cases [4,5]. Many of the samples (grown by a range of methods) were polycrystalline.…”

Section: I: Introductionmentioning

confidence: 99%

Effect of polycrystallinity on the optical properties of highly oriented ZnO grown by pulsed laser deposition

McGlynn

2004

Thin Solid Films

View full text Add to dashboard Cite

We report the results of photoluminescence and reflectance measurements on highly caxis oriented polycrystalline ZnO grown by pulsed laser deposition. The samples measured were grown under identical conditions and were annealed in-situ at various temperatures for 10-15 minutes. The band-edge photoluminescence spectra of the material altered considerably with an increase in grain size, with increased free exciton emission and observable excitonic structure in the reflectance spectra. The green band emission also increased with increasing grain size. A deformation potential analysis of the effect of strain on the exciton energy positions of the A-& B-excitons demonstrated that the experimental exciton energies couldn't be explained solely in terms of sample strain. We propose that electric fields in the samples due to charge trapping at grain boundaries are responsible for the additional perturbation of the excitons. This

show abstract

Fabrication and Optoelectronic Properties of a Transparent ZnO Homostructural Light-Emitting Diode

Cited by 250 publications

References 12 publications

ZnO light-emitting diode grown by plasma-assisted metal organic chemical vapor deposition

ZnO light-emitting diode grown by plasma-assisted metal organic chemical vapor deposition

Point defects in ZnO: an approach from first principles

Effect of polycrystallinity on the optical properties of highly oriented ZnO grown by pulsed laser deposition

Contact Info

Product

Resources

About