Exciton states and optical transitions in InGaN/GaN quantum dot nanowire heterostructures: Strong built-in electric field and dielectric mismatch effects

Zhang, Min; Shi, Junjie

doi:10.1016/j.jlumin.2011.05.007

Cited by 8 publications

(1 citation statement)

References 37 publications

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“…Among these materials, gallium nitride (GaN) has been considered as a promising candidate for thin film heterojunctions (as antireflective coating, window material, transparent emitter and back surface field material in PIN structures) and tandem solar cells due to its wide band gap (3.4 eV at 300 K), good stability at high temperature, excellent thermal conductivity and the possibility of obtaining high quality thin films with n or p type conductivity (since it is easily doped with silicon or magnesium for n or p type materials, respectively) [1,2,3,4]. GaN, generally crystallizing in the wurtzite structure (lattice constants: a = 3.189 Å, c = 5.186 Å), is a very attractive material for applications in optoelectronic devices because it has a direct band gap and it is easy to control its carrier concentration and conductivity type [5,6]. Also, the incorporation of Indium in the GaN matrix allows the band gap modulation in In x Ga x −1 N alloys.…”

Section: Introductionmentioning

confidence: 99%

Photoluminescence Study of Gallium Nitride Thin Films Obtained by Infrared Close Space Vapor Transport

et al. 2013

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Photoluminescence (PL) studies in GaN thin films grown by infrared close space vapor transport (CSVT-IR) in vacuum are presented in this work. The growth of GaN thin films was done on a variety of substrates like silicon, sapphire and fused silica. Room temperature PL spectra of all the GaN films show near band-edge emission (NBE) and a broad blue and green luminescence (BL, GL), which can be seen with the naked eye in a bright room. The sample grown by infrared CSVT on the silicon substrate shows several emission peaks from 2.4 to 3.22 eV with a pronounced red shift with respect to the band gap energy. The sample grown on sapphire shows strong and broad ultraviolet emission peaks (UVL) centered at 3.19 eV and it exhibits a red shift of NBE. The PL spectrum of GaN films deposited on fused silica exhibited a unique and strong blue-green emission peak centered at 2.38 eV. The presence of yellow and green luminescence in all samples is related to native defects in the structure such as dislocations in GaN and/or the presence of amorphous phases. We analyze the material quality that can be obtained by CSVT-IR in vacuum, which is a high yield technique with simple equipment set-up, in terms of the PL results obtained in each case.

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