@techreport{oai:sucra.repo.nii.ac.jp:00011600,
 author = {鎌田, 憲彦},
 month = {2018-01-23},
 note = {KAKEN: 10650035, By observing the intensity change of band-to-band photoluminescence(PL) due to the superposition of a below-gap excitation(BGE) light on a onventional above-gap excitation(AGE) light, a quantitative study on nonradiative recombination(NRR) centers in bulk and multiple quantum well(MQW) miconductors became possible. Lowering the AGE density down to the regime of single-photon-counting detection improved the sensitivity of finding NRR centers. The energy distribution of the NRR centers inside forbidden gap and their spatial distribution in MQW structures became clear by tuning the energy of both AGE and BGE systematically.
Various levels were detected in GaAs/AIGaAs MQW structures grown by MOCVD technique, reflecting their growth temperature, composition and doping concentrations. We analyzed the PL intensity increase or decrease due to the BGE based on a one-level model or a two-levels model, respectively, after SRH statistics. Trap parameters were determined self-consistently by considering the AGE and BGE density dependence of the PL intensity change. Contrary to uniformly doped samples, a distinct absence of NRR centers in modulation-doped well layers became clear for the first time. In InGaN/GaN MQW structures, NRR centers were found in GaN layers and their energy distribution was consistent with the previous band diagram including the yellow luminescence band.
Since the method is non-contacting and non-destractive, it can be utilized for characterizing various below-gap states in wafers and device structures, through which optimization of each processing step and the structure of light emitting devices becomes possible., 別刷論文削除, text, application/pdf},
 title = {発光デバイス用半導体の非発光再結合準位スペクトロスコピー},
 year = {},
 yomi = {カマタ, ノリヒコ}
}