Crystallinity Control of Silicon Thin Films for High-Efficiency Solar Cells by Two-Step Growth Method
| Project/Area Number |
14580533
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
エネルギー学一般
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| Research Institution | Tokyo University of Agriculture and Technology |
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Principal Investigator |
KAMISAKO Koichi Tokyo University of Agriculture and Technology, Faculty of Technology, Associate Professor, 工学部, 助教授 (40092481)
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| Project Period (FY) |
2002 – 2003
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| Project Status |
Completed (Fiscal Year 2003)
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| Budget Amount *help |
¥2,300,000 (Direct Cost: ¥2,300,000)
Fiscal Year 2003: ¥1,100,000 (Direct Cost: ¥1,100,000)
Fiscal Year 2002: ¥1,200,000 (Direct Cost: ¥1,200,000)
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| Keywords | microcrystalline silicon / hydrogen radical CVD / two-step growth / reflectivity / surface roughness / XRD / 微結晶シリコン薄膜 / 水素ラジカルCVD法 / 紫外線反射率 / 薄膜構造 / バイアス電圧印加 |
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| Research Abstract |
To control crystallinity of silicon thin films, microcrystalline silicon thin films were prepared by hydrogen radical CVD method and their structure and properties were evaluated. Especially, to clarify effect of amorphous initial layer and crystalline growth process, crystallinity and electrical properties of thin films were estimated in detail. Substrate dependence of film structure was compared by using glass and Al substrates. Moreover, two-step growth was done by changing gas phase reaction with substrate position. As a result, the following matters were clarified.
The microcrystalline films prepared at 200℃ showed (111) preferential orientation and the grain size estimated from XRD was 30nm in maximum. However, the average grain size obtained from AFM was changed from 90nm to 270nm and simultaneously the surface roughness was increased. These results suggest that microcrystalline grains grow, collide and coaggregate. The vertical electrical conductivity was very small compared to the lateral one and nearly equal to the values of amorphous films. This result shows the effect of amorphous initial layer. By raising the substrate temperature from 200 to 350℃, the thickness of amorphous initial layer was decreased. The experiments of two-step growth showed that, by regulating SiH4 flow rate, growth rate can be increased and crystallinity of films can be controlled.
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Report
(3 results)
Research Products
(12 results)
