Growth of InAs(Bi)/GaAs Quantum Dots under a Bismuth Surfactant at High and Low Temperature

Abstract

Indium arsenide quantum dots are of great interest for next-generation telecom optoelectronics if their emission wavelength can be red shifted into the correct range. One method to achieve this is the deposition of a surfactant, such as bismuth, during quantum dot growth. Here, we present a series of indium arsenide quantum dot layers grown using several bismuth fluxes and two different growth temperatures. The effects of bismuth flux on quantum dot morphology and optical properties are studied by atomic force microscopy and photoluminescence measurements. Bimodal distributions of quantum dots are seen at low growth temperature, while at high temperature, a single dominant distribution is seen in most of the layers. A medium bismuth flux was seen to produce the highest integrated photoluminescence intensity at high growth temperature, whereas intensity saturates between medium and high fluxes at low growth temperatures. A significant increase in uncorrected aspect ratio seen for the layer grown with a low bismuth flux at high growth temperature presents a new opportunity for control of quantum dot morphology using bismuth.