液滴蚀刻锥壳 GaAs 量子点中与点尺寸相关的激子

Dot-Size Dependent Excitons in Droplet-Etched Cone-Shell GaAs Quantum Dots.

作者信息

Heyn Christian, Gräfenstein Andreas, Pirard Geoffrey, Ranasinghe Leonardo, Deneke Kristian, Alshaikh Ahmed, Bester Gabriel, Hansen Wolfgang

机构信息

Center for Hybrid Nanostructures (CHyN), University of Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany.

Physical Chemistry and Physics Departments, University of Hamburg, HARBOR Build., Luruper Chaussee 149, 22761 Hamburg, Germany.

出版信息

Nanomaterials (Basel). 2022 Aug 28;12(17):2981. doi: 10.3390/nano12172981.

DOI:10.3390/nano12172981

PMID:36080018

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC9457581/

Abstract

Strain-free GaAs quantum dots (QDs) are fabricated by filling droplet-etched nanoholes in AlGaAs. Using a template of nominally identical nanoholes, the QD size is precisely controlled by the thickness of the GaAs filling layer. Atomic force microscopy indicates that the QDs have a cone-shell shape. From single-dot photoluminescence measurements, values of the exciton emission energy (1.58...1.82 eV), the exciton-biexciton splitting (1.8...2.5 meV), the exciton radiative lifetime of bright (0.37...0.58 ns) and dark (3.2...6.7 ns) states, the quantum efficiency (0.89...0.92), and the oscillator strength (11.2...17.1) are determined as a function of the dot size. The experimental data are interpreted by comparison with an atomistic model.

摘要

通过填充AlGaAs中液滴蚀刻的纳米孔来制备无应变的GaAs量子点（QD）。使用名义上相同的纳米孔模板，量子点的尺寸由GaAs填充层的厚度精确控制。原子力显微镜表明量子点具有锥壳形状。通过单点光致发光测量，确定了激子发射能量（1.58...1.82 eV）、激子-双激子分裂（1.8...2.5 meV）、亮态（0.37...0.58 ns）和暗态（3.2...6.7 ns）的激子辐射寿命、量子效率（0.89...0.92）以及振子强度（11.2...17.1）与量子点尺寸的函数关系。通过与原子模型比较来解释实验数据。