Research on the Quantum confinement of Carriers in the Type-I Quantum Wells Structure

TL;DR

This paper reviews the energy band structure of quantum wells, revealing how carriers can escape under electric fields, challenging traditional beliefs about carrier confinement in low-dimensional structures.

Contribution

It introduces a new interpretation of quantum well energy bands considering all wave vectors, explaining carrier escape mechanisms and aiding in device design.

Findings

Carrier escape occurs under electric fields in quantum wells.

Energy band structure is a superposition of bulk and quantization energies.

Comprehensive summary of energy band scenarios in quantum wells.

Abstract

Quantum confinement is recognized to be an inherent property in low-dimensional structures. Traditionally it is believed that the carriers trapped within the well cannot escape due to the discrete energy levels. However, our previous research has revealed efficient carrier escape in low-dimensional structures, contradicting this conventional understanding. In this study, we review the energy band structure of quantum wells considering it as a superposition of the bulk material dispersion and quantization energy dispersion resulting from the quantum confinement across the whole Brillouin zone. By accounting for all wave vectors, we obtain a certain distribution of carrier energy at each quantization energy level, giving rise to the energy subbands. These results enable carriers to escape from the well under the influence of an electric field. Additionally, we have compiled a comprehensive summary of various energy band scenarios in quantum well structures, relevant to carrier transport. Such a new interpretation holds significant value in deepening our comprehension of low-dimensional energy bands, discovering new physical phenomena, and designing novel devices with superior performance.