Thin Ga(Sb,P)/GaP quantum wells with indirect band gap: Crystal structure, energy spectrum, exciton recombination and spin dynamics

IF 3.3 3区物理与天体物理 Q2 OPTICS

Journal of Luminescence Pub Date : 2024-09-11 DOI:10.1016/j.jlumin.2024.120888

T.S. Shamirzaev , D.R. Yakovlev , D. Kudlacik , C. Harkort , M.A. Putyato , A.K. Gutakovskii , M. Bayer

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引用次数: 0

Abstract

Heterostructures with thin GaSb layers embedded in a GaP matrix are studied by transmission electron microscopy as well as steady-state and transient photoluminescence. For a single, one monolayer thick deposition with subsequent overgrowth, nonmonotonic Sb segregation results in self-organized Ga(Sb,P) double-quantum well (QW) formation. One QW is positioned deep in GaP at the designated place according to the heterostructure design, and the other QW is in the near surface region after 40 monolayers of GaP overgrowth. Both QWs are characterized by an indirect band gap. The band alignment in the QWs is identified as type I. In spite of the long (up to milliseconds) exciton lifetimes in the QWs in combination with the electron g factor of +2, the emission of the QWs demonstrates a low circular polarization degree in longitudinal magnetic fields as strong as 10 T. We demonstrate that the electron spin polarization in the Ga(Sb,P)/GaP heterostructure subject to a magnetic field occurs in the GaP layer, and spin-polarized charge carriers captured in the QWs store their spin orientation up to the millisecond time range, indicating very long spin relaxation times for the strongly localized electrons in the Ga(Sb,P)/GaP QWs.

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具有间接带隙的薄 Ga(Sb,P)/GaP 量子阱：晶体结构、能谱、激子重组和自旋动力学

我们通过透射电子显微镜以及稳态和瞬态光致发光研究了嵌入 GaP 基体的 GaSb 薄层异质结构。在单层厚沉积和后续过生长的情况下，非单调的锑偏析导致自组织 Ga（Sb，P）双量子阱（QW）的形成。根据异质结构设计，一个 QW 位于 GaP 的深处指定位置，而另一个 QW 则位于经过 40 个单层 GaP 过度生长后的近表面区域。两个 QW 都具有间接带隙的特征。尽管 QW 中的激子寿命较长（长达几毫秒），电子 g 系数为 +2，但在 10 T 的纵向磁场中，QW 的发射仍表现出较低的圆极化程度。我们证明，受磁场影响的 Ga（Sb,P）/GaP 异质结构中的电子自旋极化发生在 GaP 层中，QW 中捕获的自旋极化电荷载流子可在毫秒级时间范围内存储其自旋取向，这表明 Ga（Sb,P）/GaP QW 中强局域化电子的自旋弛豫时间非常长。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Journal of Luminescence 物理-光学

CiteScore

6.70

自引率

13.90%

发文量

850

审稿时长

3.8 months

期刊介绍： The purpose of the Journal of Luminescence is to provide a means of communication between scientists in different disciplines who share a common interest in the electronic excited states of molecular, ionic and covalent systems, whether crystalline, amorphous, or liquid. We invite original papers and reviews on such subjects as: exciton and polariton dynamics, dynamics of localized excited states, energy and charge transport in ordered and disordered systems, radiative and non-radiative recombination, relaxation processes, vibronic interactions in electronic excited states, photochemistry in condensed systems, excited state resonance, double resonance, spin dynamics, selective excitation spectroscopy, hole burning, coherent processes in excited states, (e.g. coherent optical transients, photon echoes, transient gratings), multiphoton processes, optical bistability, photochromism, and new techniques for the study of excited states. This list is not intended to be exhaustive. Papers in the traditional areas of optical spectroscopy (absorption, MCD, luminescence, Raman scattering) are welcome. Papers on applications (phosphors, scintillators, electro- and cathodo-luminescence, radiography, bioimaging, solar energy, energy conversion, etc.) are also welcome if they present results of scientific, rather than only technological interest. However, papers containing purely theoretical results, not related to phenomena in the excited states, as well as papers using luminescence spectroscopy to perform routine analytical chemistry or biochemistry procedures, are outside the scope of the journal. Some exceptions will be possible at the discretion of the editors.