Analysis of Threshold Current Behavior for Bulk and Quantum-Well Germanium Laser Structures

被引：39

作者：

Cai, Yan ^{[1
]}

Han, Zhaohong ^{[1
]}

Wang, Xiaoxin ^{[2
]}

Camacho-Aguilera, Rodolfo E. ^{[1
]}

Kimerling, Lionel C. ^{[1
]}

Michel, Jurgen ^{[1
]}

Liu, Jifeng ^{[2
]}

机构：

[1] MIT, Microphoton Ctr, Cambridge, MA 02139 USA

[2] Dartmouth Coll, Thayer Sch Engn, Hanover, NH 03755 USA

来源：

IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS | 2013年 / 19卷 / 04期

关键词：

Diode lasers; germanium (Ge); integrated optoelectronics; quantum-well (QW) lasers; GE-ON-SI; INFRARED-ABSORPTION; SILICON; NANOCRYSTALS; CONFINEMENT; DOTS;

D O I：

10.1109/JSTQE.2013.2247573

中图分类号：

TM [电工技术]; TN [电子技术、通信技术];

学科分类号：

0808 ; 0809 ;

摘要：

We analyze the optical gain of tensile-strained, n-germanium (n-Ge) material taking bandgap narrowing (BGN) for heavily doped Ge into account. Both the direct bandgap and indirect bandgap are narrowed by 60 meV. Our new modeling explains the wide lasing spectrum of 1520-1700 nm in electrically pumped Ge lasers. The calculated materials gain can reach 1000 cm(-1) when the injected carrier density is similar to mid-10(19) cm(-3) with a combination of 0.25% tensile strain and 4.5x10(19) cm(-3) n-type doping. The threshold current density is estimated to be 0.53 kA/cm(2) for an optimized edge-emitting double-heterojunction Ge device, comparable to bulk III-V lasers. We also review current progress on Ge quantum-well (QW) structures. The threshold current density of most Ge QW structures is similar to bulk Ge. Only tensile-strained QWs show reduced threshold currents.

引用

页数：9

共 29 条

[11] A SIMPLE EXPRESSION FOR BAND-GAP NARROWING (BGN) IN HEAVILY DOPED SI, GE, GAAS AND GEXSI1-X STRAINED LAYERS [J].