Electronic Coupling in Nanoscale InAs/GaAs Quantum Dot Pairs Separated by a Thin Ga(Al)As Spacer

Yao Liu; Baolai Liang; Qinglin Guo; Shufang Wang; Guangsheng Fu; Nian Fu; Zhiming M Wang; Yuriy I Mazur; Gregory J Salamo

doi:10.1186/s11671-015-0973-5

Electronic Coupling in Nanoscale InAs/GaAs Quantum Dot Pairs Separated by a Thin Ga(Al)As Spacer

Nanoscale Res Lett. 2015 Dec;10(1):973. doi: 10.1186/s11671-015-0973-5. Epub 2015 Jun 26.

Authors

Yao Liu¹, Baolai Liang, Qinglin Guo, Shufang Wang, Guangsheng Fu, Nian Fu, Zhiming M Wang, Yuriy I Mazur, Gregory J Salamo

Affiliation

¹ College of Physics Science & Technology, Hebei University, Baoding, 071002, People's Republic of China.

Abstract

The electronic coupling in vertically aligned InAs/GaAs quantum dot (QD) pairs is investigated by photoluminescence (PL) measurements. A thin Al0.5Ga0.5As barrier greatly changes the energy transfer process and the optical performance of the QD pairs. As a result, the QD PL intensity ratio shows different dependence on the intensity and wavelength of the excitation laser. Time-resolved PL measurements give a carrier tunneling time of 380 ps from the seed layer QDs to the top layer QDs while it elongates to 780 ps after inserting the thin Al0.5Ga0.5As barrier. These results provide useful information for fabrication and investigation of artificial QD molecules for implementing quantum computation applications.