Journal Club do Departamento de Física dos Materiais e Mecânica
Nesta semana o aluno de doutorado Ahmad Alzeidan, do Laboratório de Novos Materiais Semicondutores (LNMS-MBE), apresentará o artigo:
"StranskiKrastanov InAs/GaAsSb quantum dots coupled with sub-monolayer quantum dot stacks as a promising absorber for intermediate band solar cells"
Yeongho Kim et al.
Appl. Phys. Lett. 111, 073103 (2017);
https://doi.org/10.1063/1.4999437
Abstract:
The optical properties of the StranskiKrastanov (SK) grown InAs/GaAsSb quantum dots (QDs) coupled to sub-monolayer (SML) InAs QD stacks are investigated using photoluminescence (PL) spectroscopy. The PL emission peak of the SK QDs shifts to shorter wavelengths with increasing the number of SML stacks (NSML) due to the increasing strain fields from the SML QDs. The PL peak energy is linearly increased with increasing the cube root of excitation power, with a different ratio of the absorption coefficient to radiative recombination rate for all the QD samples. The total carrier lifetime for the SK QDs is increased with increasing NSML, most probably caused by the increase in the ground-state transition energy of the SK QDs. The nonmonotonic behavior of the thermal activation energy of electrons in the SK QDs is observed due to the NSML-dependent variation of the strain and Coulombic interaction within the QDs.
Data: 22 de novembro de 2017 (quarta-feira)
Horário: às 12h10min
Local: Sala de Seminários José Roberto Leite - Edifício Alessandro Volta (bloco C)
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Secretaria do Departamento de Física dos
Materiais e Mecânica - DFMT
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