Author(s):
Godoy, Marcio Peron Franco de, 1975- ; Nakaema, Marcelo Kiyoshi Kian, 1971- ; Iikawa, Fernando, 1960- ; Brasil, Maria José Santos Pompeu, 1961- ; Lopes, João Marcelo Jordão ; Bortoleto, José Roberto Ribeiro, 1974- ; Cotta, Mônica Alonso, 1963-
Date: 2007
Persistent ID: https://hdl.handle.net/20.500.12733/1666169
Origin: Oasisbr
Subject(s): Pontos quânticos; Fotoluminescência; Semicondutores; Quantum dots; Photoluminescence; Semiconductors; Artigo original; Pontos quânticos; Pontos quânticos; Fotoluminescência; Fotoluminescência; Semicondutores; Semicondutores; Quantum dots; Quantum dots; Photoluminescence; Photoluminescence; Semiconductors; Semiconductors; Artigo original; Artigo original
Description
Agradecimentos: The authors thank J. H. Clerici and K. O. Vicaro for helpful support in AFM measurements, Milton M. Tanabe for technical support, CME-UFRGS for TEM measurements, and the Brazilian Synchrotron Laboratory (Laboratório Nacional de Luz Sincrotron—LNLS) for GID measurements. We also acknowledge the financial support from CAPES, CNPq, FAPESP, and FAEP
Abstract: We investigated structural and optical properties of type-II InP/GaAs quantum dots using reflection high energy electron diffraction, transmission electron microscopy, atomic force microscopy, grazing incidence x-ray diffraction, and photoluminescence techniques. The InP dots present an efficient optical emission even when they are uncapped, which is attributed to the low surface recombination velocity in InP. We compare the difference in the optical properties between surface free dots, which are not covered by any material, with dots covered by a GaAs capping layer. We observed a bimodal dispersion of the dot size distribution, giving rise to two distinct emission bands. The results also revealed that the strain accumulated in the InP islands is slightly relieved for samples with large InP amounts. An unexpected result is the relatively large blue shift of the emission band from uncapped samples as compared to capped dots
COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPES
CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQ
FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP
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