Monolithically integrated 940 nm half VCSELs on bulk Ge substrates

TL;DR

This paper demonstrates the successful monolithic growth of high-quality 940 nm half VCSELs on bulk germanium substrates, paving the way for scalable mass production of AlGaAs-based VCSELs.

Contribution

It introduces a method for growing high-quality AlGaAs structures on Ge substrates, enabling monolithic VCSEL fabrication on larger wafers.

Findings

Comparable photoluminescence and reflectance spectra to GaAs-based structures

Smooth morphology and uniformity of grown layers

Supports full VCSEL growth on Ge substrates

Abstract

High quality n-type AlGaAs distributed Bragg reflectors (DBRs) and lnGaAs multiple quantum wells were successfully monolithically grown on 4-inch off-cut Ge (100) wafers. The grown structures have photoluminescence spectra and reflectance spectra comparable to those grown on conventional bulk GaAs wafers and have smooth morphology and reasonable uniformity. These results strongly support full VCSEL growth and fabrication on larger-area bulk Ge substrates for the mass production of AlGaAs-based VCSELs.