Polycrystalline silicon(poly-Si) thin films were prepared on quartz substrates by rapid thermal chemical vapor deposition(RTCVD) system,and their structures were studied by XRD,SEM and TEM,respectively.XRD spectra exh...Polycrystalline silicon(poly-Si) thin films were prepared on quartz substrates by rapid thermal chemical vapor deposition(RTCVD) system,and their structures were studied by XRD,SEM and TEM,respectively.XRD spectra exhibit a single strong(220) diffraction peak,which indicates that the poly-Si films are preferentially <110> oriented.Plane-view SEM images show that the surface of the poly-Si films is composed of large numbers of polygonal pyramid grains with different sizes,and cross-section SEM images further indicate that they are columnar grains with growth direction perpendicular to substrate surface.TEM observation results demonstrate that there are a lot of twin crystals including one-order,two-order and high-order(≥3) twin crystals in the poly-Si films.The above experimental results can not be elucidated by the conventional opinion on growth behavior of poly-Si films prepared by atmosphere pressure chemical vapor deposition(APCVD),but can be explained by the Ino's multiply twinned particles(MTPs) model found in the face centered cubic metal films.According to the above experimental results and Ino's model,we tend to think that nucleation and grain growth of poly-Si films deposited by RTCVD on quartz substrates are based on the formation of MTPs,and then these MTPs form the continuous films in an island growth mode.展开更多
A new preparing technology, very high frequency plasma assisted reactive thermal chemical vapour deposition （VHFPA-RTCVD）, is introduced to prepare SiGe：H thin films on substrate kept at a lower temperature. In the...A new preparing technology, very high frequency plasma assisted reactive thermal chemical vapour deposition （VHFPA-RTCVD）, is introduced to prepare SiGe：H thin films on substrate kept at a lower temperature. In the previous work, reactive thermal chemical vapour deposition （I^TCVD） technology was successfully used to prepare SiGe：H thin films, but the temperature of the substrate needed to exceed 400℃. In this work, very high frequency plasma method is used to assist RTCVD technology in reducing the temperature of substrate by largely enhancing the temperature of reacting gases on the surface of the substrate. The growth rate, structural properties, surface morphology, photo- conductivity and dark-conductivity of SiGe：H thin films prepared by this new technology are investigated for films with different germanium concentrations, and the experimental results are discussed.展开更多
Poly-crystalline silicon thin film has big potential of reducing the cost of solar cells. In this paper the preparation of thin film is introduced, and then the morphology of poly-crystalline thin film, is discussed. ...Poly-crystalline silicon thin film has big potential of reducing the cost of solar cells. In this paper the preparation of thin film is introduced, and then the morphology of poly-crystalline thin film, is discussed. On the film we developed poly-crystalline silicon thin film solar cells with efficiency up to 6.05% without anti-reflection coating.展开更多
基金supported by the National Natural Science Foundation of China (50802118)National High-Tech Research and Developmen Program of China (2006AA05Z409)+1 种基金China Postdoctor Foundation (20060390741)Natural Science Foundation of Guangdong province (5300577)
文摘Polycrystalline silicon(poly-Si) thin films were prepared on quartz substrates by rapid thermal chemical vapor deposition(RTCVD) system,and their structures were studied by XRD,SEM and TEM,respectively.XRD spectra exhibit a single strong(220) diffraction peak,which indicates that the poly-Si films are preferentially <110> oriented.Plane-view SEM images show that the surface of the poly-Si films is composed of large numbers of polygonal pyramid grains with different sizes,and cross-section SEM images further indicate that they are columnar grains with growth direction perpendicular to substrate surface.TEM observation results demonstrate that there are a lot of twin crystals including one-order,two-order and high-order(≥3) twin crystals in the poly-Si films.The above experimental results can not be elucidated by the conventional opinion on growth behavior of poly-Si films prepared by atmosphere pressure chemical vapor deposition(APCVD),but can be explained by the Ino's multiply twinned particles(MTPs) model found in the face centered cubic metal films.According to the above experimental results and Ino's model,we tend to think that nucleation and grain growth of poly-Si films deposited by RTCVD on quartz substrates are based on the formation of MTPs,and then these MTPs form the continuous films in an island growth mode.
基金supported by the State Key Development Program for Basic Research of China (Grant Nos 2006CB202602 and 2006CB202603)the Tianjin Research Foundation for Basic Research,China (Grant No 08JCZDJC 22200)International Cooperative Project of the Ministry of Science and Technology,China (Grant No 2006DFA62390)
文摘A new preparing technology, very high frequency plasma assisted reactive thermal chemical vapour deposition （VHFPA-RTCVD）, is introduced to prepare SiGe：H thin films on substrate kept at a lower temperature. In the previous work, reactive thermal chemical vapour deposition （I^TCVD） technology was successfully used to prepare SiGe：H thin films, but the temperature of the substrate needed to exceed 400℃. In this work, very high frequency plasma method is used to assist RTCVD technology in reducing the temperature of substrate by largely enhancing the temperature of reacting gases on the surface of the substrate. The growth rate, structural properties, surface morphology, photo- conductivity and dark-conductivity of SiGe：H thin films prepared by this new technology are investigated for films with different germanium concentrations, and the experimental results are discussed.
基金This work was supported by the Chinese Academy of Sciences within the Hundred Talent Project(No.99-019-422288)National High Technical Research and Development Programme of China(No.2001AA513060).
文摘Poly-crystalline silicon thin film has big potential of reducing the cost of solar cells. In this paper the preparation of thin film is introduced, and then the morphology of poly-crystalline thin film, is discussed. On the film we developed poly-crystalline silicon thin film solar cells with efficiency up to 6.05% without anti-reflection coating.
