공학DB
전남대학교 광 전자막박 연구실
실험실 소개 이미지
실험실 정보안내
지도교수 박현수
전공분류 재료 및 파괴부문(Materials and Fracture),
주소 광주광역시 북구 용봉로 77
전화 062-530-1705
홈페이지 http://altair.chonnam.ac.kr/~photon/
실험실소개

 


 Photonic and Electronic Thin Flim Laboratory has been established in 1999 ain Chonnam National University. Our laboratory concentrates on the development of aadvanced photonic and electronic thin films such as wide bandgap materials a(GaN and ZnO), ferroelectric materials (Pb(Mg,Nb)O3 and Pb(Mg,Ta)O3), and optical aglasses (silicate glasses and tellurite glasses). Thin films are prepared by various adeposition processes such as sputtering, MOCVD, PLD, and chemical solution adeposition. Their optical, structural, and electrical properties are characterized, and a then the characterization results are used to control the process variables for the apurpose of the formation of high quality thin films. There are five faculty members, two apost-docs, three Ph.D. students, and fifteen master students in the laboratory. aFundings are coming from variety sources like NRL supported by the Korean Ministry aof Science and Technology, other government agencies, and industries. We are aactively doing collaboration works with universities, industries, and research institutes adomestically as well as internationally and reporting more than 20 SCI papers a year.

연구분야

 

1. Optoelectronics

Light emitting diodes (LEDs) and laser diodes (LDs) are essential components for optical telecommunications and information technology. Very recently, the research on ZnO has been revived because of its potential application as short-wavelength (UV and blue) LEDs and LDs. ZnO is a direct-band-gap semiconductor with a wide energy gap of 3.3 eV at room temperature (RT) and being thus considered as a promising material for these devices. Moreover, it has a higher exiton binding energy of 60 meV at RT comparing to GaN (28 meV) that is currently used for UV/blue LEDs and lasers. This higher exciton binding energy may produce more efficient lasers at RT. The recent reports of success in optically pumped lasing in epitaxial ZnO thin films have further stimulated great interest in ZnO material. In addition, the band gap energy of ZnO can be tuned by alloying with MgO and CdO. Furthermore, thin films of ZnO having a good quality can be grown at much lower temperatures than GaN, which enables the growth of ZnO on Si or glass substrates. One of the main obstacles in the realization of an UV/blue light emitter using ZnO material is the difficulty in making good p-type ZnO. Some research groups claimed the success in growing p-type ZnO films. However, it is general opinion that p-type ZnO has not been achieved yet from the viewpoint of reproducibility and quality for practical application.  

Our laboratory has been depositing homo- and hetero-epitaxial ZnO thin films using MOCVD, sputtering, and PLD on various substrates. Through doping and plasma activation, we are attempting to make reliable p-type ZnO films. We also try to fabricate and realize p-n junction diodes, bandgap engineering, and multiquantum well structures in ZnO-based material systems.

 

2. Ferroelectrics

Oxides display a wide variety of physical properties that are well suited for integration with semiconductor-based electronic and optoelectronic devices. Fore example, electrical conductivity in oxides can range from insulation to semiconducting to metallic to superconduction, spanning well over ten orders of magnitude. Ferroelectric oxides such as PZT, PMN, SBT display spontaneous switchable dielectric polarization as well as pyroelectricity, piezoelectricity, electro-optic effects, and high dielectric polarization as well as pyroelectricity, piezoelectricity, electro-optic effects, and high dielectric permittivity. (Fig. 1) Oxides can also display high optical gain and ferromagnetic effect. In order to directly integrate these properties with semiconductor devices, it is generally necessary to grow the oxide layer epitaxially either to provide a suitable template for subsequent epitaxial active layers or to optimize the electronic and optical properties of the oxide. For the growth of high quality epitaxial oxide thin films on Si substrates, growth of appropriate buffer layers such as TiN, SrTiO3, is required. The problems of lattice

mismatch and the possible oxidation of Si substrate during the preparation of oxide thin films can be avoided by using of appropriate buffer layers. There for it is the goal of our research to grow heteroepitaxial oxide thin films on Si substrates by using buffer layers. We are especially interested in relaxor ferroelectric thin films (Pb(Mg1/3,Nb2/3)O3-PbTiO3) and conducting buffer layers (TiN). (Figs. 2 & 3)

We are trying to grow high quality epitaxial oxide films and buffer layers using sputtering, pulsed laser deposition, chemical solution deposition, and chemical vapor deposition. We are also trying to characterize theire electrical and optical properties and to understand the epitaxy mechanisms in different film/substrate systems

 

3.  Optical Devices

Integrated optics devices are now considered for applications in additioin to optical communication (e.g., sensors, optical computers). A waveguide forms the basis for integrated optical devices. Different technologies have been employed to achieve waveguides in various materials. Glass is an interesting substrate material for integrated optics because of its relatively low cost, excellent transparency, high threshold to optical damage, and availability in substantially large sizes. It is also mechanically very rigid. Furthermore, glass substrates are amorphous, and it is easier to produce polarization insensitive components in glass. In addition, the refractive index of glasses used in integrated optics (e.g., silicate, phosphate, tellurite) is close to that of optical fiber and therefore, coupling losses between the waveguides made in glass and the optical fibers are smaller. Faculty members and students are designing and fabricating ilicate and tellurite glasses for laser and photonics applications, such as waveguide lasers, fiber amplifiers, and integrated optics. Also facilities exist for making both surface and buried waveguides for making passive and active components for the optical communication applications. We are preparing glass thin films using a number of thin film deposition facilities including FHD, AFD, CVD, and Sputtering. We are also trying to haracterize their optical and structural properties and to understand the effects of process variables on the optical properties of planar waveguides formed glass thin films.


 

연구성과
김선훈, 박신철, 김진혁, 문종하, 이병택
기판 종류에 따른 박막형 SnO2 가스 센서의 응답특성
한국재료학회지, , Vol. 0, No. 0, pp. 0~ 0

성경필, 최동수, 김진혁, 문종하, 명태호, 이병택
Al2O3 표면보호층이 박막형 SnO2 가스센서의 감지특성에 미치는 영향
한국재료학회지, , Vol. 0, No. 0, pp. 0~ 0

하우종, 문종하, 이병택, 박현수,
분위기 열처리가 Ca-doped YCrO3의 전기적 특성에 미치는 영향
한국재료학회지 , , Vol. 0, No. 0, pp. 0~ 0

김성대, 정석용, 이병택, 허증수
BCl3/H2/Ar 유도결합 플라즈마를 이용한 GaN의 건식 식각에 관한 연구
한국재료학회지, , Vol. 0, No. 0, pp. 0~ 0

이병택, 박철희, 김성대, 김호성
BCl3/O2/Ar 유도결합 플라즈마를 이용한 InP의 건식 식각에 관한 연구
한국진공학회지, , Vol. 0, No. 0, pp. 0~ 0

프로젝트
[Method of Making a Buried Heterostructure Laser ] B.-T. Lee, T.R. Hayes, R.F. Kalicek, Jr., and R.A. Logan Patent Application, Serial No. 07/954,648

[가스센서의 다공성 표면보호층 제조방법] 김진혁, 문종하, 성경필, 이병택 국내 출원번호 10-2000-0007702

[실리콘 카바이드 메사 측벽의 각도 조절 방법 ] 이병택, 공성민 국내 출원 10-2001-0076980