학회 |
한국재료학회 |
학술대회 |
2008년 가을 (11/07 ~ 11/07, 차세대융합기술연구원) |
권호 |
14권 2호 |
발표분야 |
반도체재료 |
제목 |
High-Photoconductive Characteristics of CdS and PbS Thin Films Grown by Chemical Bath Deposition. |
초록 |
Cadmium sulphide (CdS) thin films have received a growing interest in these days due to their electro-optical properties that are suitable for applications in the field of optoelectronic devices, particularly solar cells and photo detectors and it is one of the most sensitive photoconductors in the visible light regime. A wide range of world wide research work is going on CdS to use in stealth radome applications for defense purpose. As CdS is a good photoconductor it can acts as an insulator for the transmit signal and acts as a metallic material for the block signal. Although high-quality CdS can be produced by metalorganic chemical vapor deposition or molecular beam epitaxy, the fabrication cost increases significantly. Chemical bath deposition (CBD) is alternative approach to synthesize high-quality polycrystalline CdS thin films on large-scale wafers including flexible substrates at a low cost. In this study, polycrystalline CdS thin films were successfully deposited by CBD method on various substrates such as glass and Si. The CdS thin films were grown at low molar concentration of sulfur solutions i.e. 1:0.125 for getting high conductivity and studied the variation in the photo, dark sheet resistance and photosensitivity values by changing the NH3 volume. The thin films prepared from low molar concentrations of sulfur (S) and at the grow temperature of 80 oC have shown low sheet resistance values due to the presence of more S vacancies. It was observed that not only the concentration ratio of ‘Cd’ and ‘S’, but also the concentrations of NH3 and TEA placed an important role to determine the photoconductive characteristics of CdS films. It also studied that the CdS thin films grown at equal molarities of ‘Cd’ and ‘S’ solutions, but with lower volumes of ‘S’ than ‘Cd’ solutions give very low photo sheet resistance of 2.5× 103 Ω∕□ with high photosensitivity of 5 ×109. Research work is also proceeding with different compositions of Cd1-xPbxS and CdS1-xSex thin films. We will further discuss the growth mechanism and photoconductive characteristics of CdS films and it’s various doping compositions with Pb and Se by CBD. |
저자 |
Challa Kiran Kumar1, Nguyen Thi Quynh Hoa2, Seung-Hee Kang3, Soon-Gil Yoon4, Eui-Tae Kim5, Geun Hong Kim1
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소속 |
1Department of Materials Engineering, 2Chungnam National Univ., 3Daejeon, 4305-764, 5Korea |
키워드 |
CdS Thin Films; High Photoconductive films; CBD; (Cd&Pb)S thin films
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E-Mail |
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