Open AccessStudy of temperature dependent electroluminescence of InGaN/GaN multiple quantum wells using low temperature scanning near-field optical microscopy
Author(s) -
Xu Gao,
Hongbin Liang,
Bai Yong-Qiang,
Kei May Lau,
Zhou Xiao
Publication year - 2005
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.54.5344
Subject(s) - electroluminescence , materials science , liquid nitrogen , quantum well , optoelectronics , photon energy , photon , semiconductor , optics , condensed matter physics , layer (electronics) , physics , laser , nanotechnology , quantum mechanics
Though GaN based semiconductor materials and devices have achieved giant commerc ial success, there were few reports on their electroluminescent near-field optic al studies at low temperature. In this paper we present our results of the elect roluminescent near-field images and spectra at both room temperature and liquid nitrogen temperature by using a lab-made low temperature scanning near-field opt ical microscope. We found that with the decreasing of sample temperature, the fl uctuation of electroluminescent intensity in the near-field images is reduced gr eatly and the peak photon energy of the spectra emitted from the quantum wells e xhibits a blue-shift at first and then a red-shift. A new spectral peak emerges at higher photon energy at liquid nitrogen temperature. According to our analysi s, this higher photon energy peak is attributed to the transition from the botto m of conduction band to the acceptor energy states in the p-GaN cap layer.