Systematic investigation on the influence of the As₄ flux on the magnetic property of (In,Cr)As quantum dots

State Key Laboratory for Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences - P.O. Box 912, Beijing 100083, China

Corresponding author: jhzhao@red.semi.ac.cn

Received: 8 August 2008
Accepted: 30 October 2008

Abstract

We study the structure, optical and magnetic characteristics of self-assembled (In,Cr)As diluted magnetic semiconductor quantum dots as a function of the As₄ flux. Increasing the surface energy by increasing the As₄ pressure leads to a smaller number of larger dots for a higher As₄ flux. The remanent magnetization measured at 5 K also increases with increasing As₄ flux, which is attributed to the enhancement of the effective Cr content due to the As₄-rich condition. We explore the possibility of tailoring magnetism by controlling the As₄/In flux ratio without changing the Cr concentration. Furthermore, extremely low-density QDs have also been successfully grown.