Annealing-Modulated Surface Reconstruction for Self-Assembly of High-Density Uniform InAs/GaAs Quantum Dots on Large Wafers Substrate
| Autor: | Niu, Xiangjun Shang, Xiangbin Su, Hanqing Liu, Huiming Hao, Shulun Li, Deyan Dai, Mifeng Li, Ying Yu, Yu Zhang, Guowei Wang, Yingqiang Xu, Haiqiao Ni, Zhichuan |
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| Jazyk: | angličtina |
| Rok vydání: | 2023 |
| Předmět: |
self-assembled quantum dots
deposition migration nucleation nucleation site quantum dot density photoluminescence spectrum full width at half maximum in situ annealing surface arsenic reconstruction phase quantum dot size distribution T-dependent state population growth rate growth temperature deposition amount arsenic influence |
| Zdroj: | Nanomaterials; Volume 13; Issue 13; Pages: 1959 |
| ISSN: | 2079-4991 |
| DOI: | 10.3390/nano13131959 |
| Popis: | In this work, we developed pre-grown annealing to form β2 reconstruction sites among β or α (2 × 4) reconstruction phase to promote nucleation for high-density, size/wafer-uniform, photoluminescence (PL)-optimal InAs quantum dot (QD) growth on a large GaAs wafer. Using this, the QD density reached 580 (860) μm−2 at a room-temperature (T) spectral FWHM of 34 (41) meV at the wafer center (and surrounding) (high-rate low-T growth). The smallest FWHM reached 23.6 (24.9) meV at a density of 190 (260) μm−2 (low-rate high-T). The mediate rate formed uniform QDs in the traditional β phase, at a density of 320 (400) μm−2 and a spectral FWHM of 28 (34) meV, while size-diverse QDs formed in β2 at a spectral FWHM of 92 (68) meV and a density of 370 (440) μm−2. From atomic-force-microscope QD height distribution and T-dependent PL spectroscopy, it is found that compared to the dense QDs grown in β phase (mediate rate, 320 μm−2) with the most large dots (240 μm−2), the dense QDs grown in β2 phase (580 μm−2) show many small dots with inter-dot coupling in favor of unsaturated filling and high injection to large dots for PL. The controllable annealing (T, duration) forms β2 or β2-mixed α or β phase in favor of a wafer-uniform dot island and the faster T change enables optimal T for QD growth. |
| Databáze: | OpenAIRE |
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