Dislocation‐Induced Structural and Luminescence Degradation in InAs Quantum Dot Emitters on Silicon

Abstract

This study probes the extent to which dislocations reduce carrier lifetimes and alter growth morphology and luminescence in InAs quantum dots (QD) grown on silicon. These heterostructures are key ingredients to achieving a highly reliable monolithically integrated light source on silicon necessary for photonic‐integrated circuits. Around 20%–30% shorter carrier lifetimes are found at spatially resolved individual dislocations at room temperature using time‐resolved cathodoluminescence spectroscopy, highlighting the strong nonradiative impact of dislocations even against the three‐dimensional confinement of QDs. Beyond these direct effects of increased nonradiative recombination, it is found that misfit dislocations in the defect filter layers employed during III–V/Si growth alter the QD growth environment to induce a crosshatch‐like variation in QD emission color and intensity when the filter layer is positioned sufficiently close to the QD emitter layer. Sessile threading dislocations generate even more egregious hillock defects that also reduce emission intensities by altering layer thicknesses, as measured by transmission electron microscopy and atom probe tomography. This work presents a more complete picture of the impacts of dislocations relevant to the development of light sources for scalable silicon photonic integrated circuits.

Strain and optical characteristics analyses of three-dimentional self-ordered multilayered SiGe nanodots by photoluminescence and Raman spectroscopy

“…In practical examples of lasers based on QDs technology, InSb and InAs QDs such as Ⅲ-Ⅴ semiconductors are proposed, [7][8][9][10] and it has been reported that high carrier injection efficiency with ultra-low threshold current has been achieved at RT in laser applications of InAs QDs. 8,9) Group III-V semiconductors are mostly direct-transition-type semiconductors, and they have very high potential for optical devices due to their high optical conversion efficiency.…”