Lasing from Glassy Ge Quantum Dots in Crystalline Si.

Martyna Grydlik,Alma Halilovic,Friedrich Schäffler,Wolfgang Jantsch,Heiko Groiss,Martin Glaser,Thomas Fromherz,Moritz Brehm,Florian Hackl

doi:10.1021/acsphotonics.5b00671

Abstract

Semiconductor light-emitters compatible with standard Si integration technology (SIT) are of particular interest for overcoming limitations in the operating speed of microelectronic devices. Light sources based on group IV elements would be SIT-compatible, but suffer from the poor optoelectronic properties of bulk Si and Ge. Here we demonstrate that epitaxially grown Ge quantum dots (QDs) in a defect-free Si matrix show extraordinary optical properties if partially amorphized by Ge-ion bombardment (GIB). In contrast to conventional SiGe nanostructures, these QDs exhibit dramatically shortened carrier lifetimes and negligible thermal quenching of the photoluminescence (PL) up to room temperature. Microdisk resonators with embedded GIB-QDs exhibit threshold behavior as well as a superlinear increase of the integrated PL intensity with concomitant line width narrowing as the pump power increases. These findings demonstrate light amplification by stimulated emission in a fully SIT-compatible group IV nanosystem.

Highlights

Semiconductor light-emitters compatible with standard Si integration technology (SIT) are of particular interest for overcoming limitations in the operating speed of microelectronic devices
Widespread applications range from power electronics, and sensors all the way toward improving on-chip data communication and processing by using guided light for data transfer instead of copper wires.[1−3] The main problem arises from the poor light emission from Si and Ge, which results from the indirect bandgap of crystalline group IV materials
The nucleation of strain-driven Ge/Si-QDs13−18 occurs on a supersaturated Ge wetting layer (WL), once a critical thickness of ∼4.2 monolayers (∼0.6 nm) is exceeded.[30]

Summary

Lasing from Glassy Ge Quantum Dots in Crystalline Si

Martyna Grydlik,‡ Florian Hackl, Heiko Groiss, Martin Glaser, Alma Halilovic, Thomas Fromherz, Wolfgang Jantsch, Friedrich Schaffler, and Moritz Brehm*,‡.

ACS Photonics

■ ACKNOWLEDGMENTS

■ REFERENCES