반도체 광전자 연구실에서는 반도체 소자 개발 및 응용을 위해 화합물 반도체의 결정 구조 , 결정 결함 , 재결합 과정 , 불순물 도핑 등에 관한 연구를 수행하고 있다.
이러한 연구를 위해 광학적 방법으로 photoluminescence, selective-excitation luminescence, time-resolved photoluminescence, cathodoluminescence 등을 수행하고 있다. 또한 불순물 에너지 레벨, 캐리어 농도, 이동도 (mobility), deep defect levels 등의 연구를 위해 Hall-effect/sheet-resistivity 측정과 deep-level transient spectroscopy (DLTS) 측정을 한다. DMS (Dilute Magnetic Semiconductor) 물성 연구와 실온의 강자성반도체를 얻기 위한 연구도 수행하고 있다.
The research effort is primarily directed toward enhancing the physical understanding of governing principles in these semiconducting materials to provide information necessary for improving the quality of crystals and conditions under which they are most suitable for particular device applications. This knowledge ultimately leads to the fabrication of state-of-the-art electronic, photonic and spintronic devices.
Optical studies are aimed at characterizing crystalline defects, impurities and the effects of hetero-structure design parameters by studying the emission spectra of bulk, hetero-structure and quantum-well material using low-temperature photoluminescence, selective-excitation luminescence, time-resolved photoluminescence and cathodoluminescence. Electrical studies concentrate on characterizing the activation energies of impurity energy levels, deep defect levels, carrier concentrations, and mobilities using temperature-dependent Hall-effect/sheet-resistivity and deep-level transient spectroscopy measurements. Studies of the magnetic characteristics of samples are made via a superconducting quantum interference device (SQUID).
Specific areas of study are currently underway toward the development of:
(1) efficient doping methods of wide-bandgap semiconductors through the ion-implantation technique;
(2) thin-film, wide-bandgap material displaying
persistent ferromagnetism through the implantation of transition metals;
(3) blue/UV semiconductor lasers and detectors through characterization of carrier recombination dynamics.