Optical Characterisation of Self Assembled Ga_xIn_(1-x)As/InP Quantum Wires

摘要

Photoluminescence measurements as a function of temperature (30 - 300K) have been carried out on self assembled Ga_xIn_(1-x)As/InP (x = 0.05, 0.15) quantum wires. The nanostructures emerge when the thickness of the deposited, strained Ga_xIn_(1-x)As layer exceeds the critical thickness for 2D grown on InP substrates. Atomic Force Microscopy (AFM) images show how the regular structure and perfection of the wires are lost as the amount of G a in the alloy increases, which is also reflected in the corresponding PL spectra. The energy and envelope of the PL spectra change with the Gallium content of the alloy. This leads to the fact that the emission energy can be tuned in the range of 1.48 - 1.72 μm, an interesting range for optoelectronics, by changing the Gallium content of the alloy. A new striking features is observed in the PL spectra. The temperature dependence of the PL spectra is strongly dependent on the Gallium content of the alloy. When x = 0.15 the Pl spectra becomes almost temperature invariant. This inference is highly relevant for temperature stable optical sources. The paper reports and discusses these interesting observations.