Semiconductor Quantum Dot Mid-infrared Lasers

I-13: Semiconductor Quantum Dot Mid-infrared Lasers
Research Team:

NTU:
Dr. Tang Xiaohong, Assistant Professor,
Dr. Chin Mee Koy, Associate Professor,
Dr. Mei Ting, Assistant Professor,

IME :
Dr. Du An Yan, Senior Research Engineer.

Abstract
Powerful and easy-to-use lasers operating in the mid-infrared (IR) range, 2m to 5m, have important variety applications in military, biomedicine, environmental protection and industry. Currently meeting these criteria are semiconductor lasers based on antimonide quantum well (QW) structures. But these lasers suffer from the decrease in output power with emitting wavelength and with operating temperature, which is caused by the reduction of hole confinement within the QW and the degradation of material. Further, un-mature fabrication process of antimonide based devices cause the high cost and low yields of the production.

In this project, we propose to develop semiconductor quantum dot structures on GaAs and InP substrate for high perform mid-IR laser applications. This includes design new material system suitable for preparing the quantum dot (QD) structures emitting at mid-IR range, develop the epitaxy growth of the QD structures on GaAs or InP substrates by using metal-organic chemical deposition (MOCVD) technology and develop MOCVD growth of the mid-IR QD diode laser structure. Using QDs as the active region in laser structure will improve the laser’s performance much in terms of lower threshold current, more stable in greater temperature range, and higher efficiency and gain. Using GaAs and InP as the substrate, the device fabrication processes are mature which enable to fabricate high perform mid-IR lasers with lower cost and high yields.

In PhRc, we have very well established MOCVD growth and III-V compound optoelectronic device processes. Variety of high quality compound semiconductor alloys, e.g. InGaAs, AlGaAs,InGaAsP, InGaP, etc and nano-structures, MQW, quantum dots, etc, have been grown. Nano-structures for optoelectronic devices, e.g. high power quantum well lasers and multiple quantum QWIP, have been grown and the devices have fabricated and tested with high performance.