Cooperative Effects in the Photoluminescence of (In,Ga)As/GaAs Quantum Dot Chain Structures
1 Department of Physics, University of Arkansas, 226 Physics Building, Fayetteville, AR, 72701, USA
2 Departamento de Fisica, Universidade Federal de Sao Carlos, 13565-905, Sao Carlos, Sao Paulo, Brazil
3 Institute of Semiconductor Physics, National Academy of Sciences of Ukraine, 45 Nauki prospect, Kiev, 03028, Ukraine
Nanoscale Research Letters 2010, 5:991-1001 doi:10.1007/s11671-010-9590-5Published: 16 April 2010
Multilayer In0.4Ga0.6As/GaAs quantum dot (QD) chain samples are investigated by means of cw and time-resolved photoluminescence (PL) spectroscopy in order to study the peculiarities of interdot coupling in such nanostructures. The temperature dependence of the PL has revealed details of the confinement. Non-thermal carrier distribution through in-chain, interdot wave function coupling is found. The peculiar dependences of the PL decay time on the excitation and detection energies are ascribed to the electronic interdot coupling and the long-range coupling through the radiation field. It is shown that the dependence of the PL decay time on the excitation wavelength is a result of the superradiance effect.