Quantum-well states and discontinuities in opto-electrical characteristics of SCH lasers

TL;DR

This study uses computer simulations to analyze how the width and depth of quantum wells in AlGaAs SCH lasers influence their electrical and optical characteristics, revealing discontinuities related to quantum states and temperature effects.

Contribution

It provides new insights into the impact of quantum well parameters on laser performance and identifies conditions causing discontinuities in laser characteristics.

Findings

Threshold current is a discontinuous function of QW width and height.

Quantum well states significantly affect laser I-V and I-L characteristics.

Discontinuities are more pronounced at low temperatures.

Abstract

Computer simulations with Synopsys' Sentaurus TCAD of opto-electrical characteristics of separate-confinement heterostructure laser based on AlGaAs are used as an example to study the role of the width and depth of Quantum Well (QW) active region on laser characteristics, I-V and I-L, below and above the lasing threshold. The device properties depend on both, the number of bound QW states and on closeness of the highest bound states to conduction or valence band offset. The lasing action may not exist at certain widths or hights of QW, the threshold current is a discontinuous function of these parameters. The effects are more pronounced at low temperatures. Discontinuities in characteristics may be observed at certain conditions in temperature dependencies of laser parameters.