Quantum well interband semiconductor lasers highly tolerant to dislocations

Laurent Cerutti,Alexei N Baranov,Daniel A Díaz Thomas,Jean-Baptiste Rodriguez,Eric Tournié,Gilles Patriarche,Marta Rio Calvo

doi:10.1364/optica.438272

Abstract

III-V semiconductor lasers integrated on Si-based photonic platforms are eagerly awaited by the industry for mass-scale applications, from interconnect to on-chip sensing. The current understanding is that only quantum dot lasers can reasonably operate at the high dislocation densities generated by the III-V-on-Si heteroepitaxy, which induces high non-radiative carrier recombination rates. Here we propose a strategy based on a type-II band alignment to fabricate quantum well lasers highly tolerant to dislocations. A mid-IR GaInSb/InAs interband cascade laser grown on Si exhibits performances similar to those of its counterpart grown on the native GaSb substrate, in spite of a dislocation density in the 10 8 c m − 2 range. Over 3800 h of continuous-wave operation data have been collected, giving an extrapolated mean time to failure exceeding 312,000 h. This validates the proposed strategy and opens the way to new integrated laser development.

Highlights

Integration of semiconductor lasers onto Si substrates has attracted considerable attention to combine the many possible photonic functions with the advantages of well-established silicon technology
An attractive approach to address this problem consists of using lasers based on quasi-direct-bandgap group-IV materials such as highly doped-Ge [1] or GeSn [2,3], but despite important efforts, adequate laser performances are still confined to low temperature or to optical pumping, and their integration remains a great challenge
The drastic degradation of the threshold current and laser lifetime with the threading dislocations (TDs) density is associated with non-radiative trap levels created by the TDs, which are typically represented as discrete energy levels within the energy bandgap

Summary

INTRODUCTION

Integration of semiconductor lasers onto Si substrates has attracted considerable attention to combine the many possible photonic functions with the advantages of well-established silicon technology. An attractive approach to address this problem consists of using lasers based on quasi-direct-bandgap group-IV materials such as highly doped-Ge [1] or GeSn [2,3], but despite important efforts, adequate laser performances are still confined to low temperature or to optical pumping, and their integration remains a great challenge. Highly efficient and robust direct bandgap III-V semiconductors have remained the most promising materials for the integration of coherent light sources onto silicon substrates. For 20 years, the integration of III-V semiconductors on Si has been intensively investigated to develop on-chip light sources in silicon photonics with high yield and cost reduction. Direct epitaxial integration is the most promising approach to provide high volume capability [8], but it is still challenging because of the formation of defects inherent to the III-V heteroepitaxy on Si, namely, threading dislocations (TDs) and antiphase boundaries (APBs).

CONCEPT FOR ACTIVE REGIONS HIGHLY TOLERANT TO DISLOCATIONS

GROWTH AND STRUCTURAL CHARACTERIZATIONS OF ICL ON SILICON SUBSTRATE

MEASUREMENTS AND RESULTS

CONCLUSION