GaAs base multi-layer self-organizing quantum dot structure and preparation method thereof

Abstract

The invention discloses a GaAs base multi-layer self-organizing quantum dot structure, and relates to the technical field of controllable growth of low-dimension semiconductor quantum dot materials and structures. The structure comprises a substrate, a buffer layer located on the substrate, N quantum dot layers located on the buffer layer and cap layers located on the N quantum dot layers, wherein a spacing layer is arranged between every two quantum dot layers. The structure is characterized in that at least one spacing layer between two adjacent quantum dot layers is double-layer, and a strain compensation layer is arranged between every two spacing layers. The invention further discloses a method for preparing the GaAs base multi-layer self-organizing quantum dot structure. According to the GaAs base multi-layer self-organizing quantum dot structure and the preparation method, strain accumulation among multiple layers of quantum dots is eliminated, accordingly mutual influence among the layers of the quantum dots is effectively reduced, the problem that quantum dots on an upper layer become large due to the strain accumulation is solved, uniformity of the multiple layers of the quantum dots can be improved, and at the same time, periodicity and mode gains of the multi-layer quantum dot structure are improved.

Description

technical field [0001] The invention relates to the technical field of controllable growth of low-dimensional semiconductor quantum dot materials and structures, in particular to a GaAs-based multilayer self-organized quantum dot structure and a preparation method thereof. Background technique [0002] Since the world's first quantum dot laser came out in 1994, GaAs-based InAs and InGaAs quantum dot (Quantum Dot, QD) materials and structures have received great attention. First of all, as a zero-dimensional semiconductor material, quantum dots have many advantages that traditional quantum wells do not have. For example, quantum dots have atomic-like discrete energy levels, making quantum dot devices smaller than traditional quantum well devices. Threshold current density, higher differential gain, higher characteristic temperature, etc. Secondly, the luminescence wavelength of the quantum well structure grown on the GaAs substrate is difficult to reach 1.3 μm, but the InAs ...

AI Technical Summary

Problems solved by technology

When the spacer layer of the adjacent quantum dot layer is thicker (greater than 50nm), the vertical upward propagation of the strain field and the strain accumulation effect will be greatly weakened, and the vertical alignment growth of the quantum dots can be greatly inhibited or even eliminated. The number of dot structure periods can be significantly increased, but the degree of overlap of electronic wave functions between multilayer quantum dots will also be greatly reduced, which ultimately seriously affects the mode gain and device performance of multilayer quantum dot devices.

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