Optical and electrical properties of undoped microcrystalline silicon deposited by the VHF-GD with different dilutions of silane in hydrogen

被引:16
作者
Beck, N
Torres, P
Fric, J
Remes, Z
Poruba, A
Stuchlikova, H
Fejfar, A
Wyrsch, N
Vanecek, M
Kocka, J
Shah, A
机构
来源
ADVANCES IN MICROCRYSTALLINE AND NANOCRYSTALLINE SEMICONDUCTORS - 1996 | 1997年 / 452卷
关键词
D O I
10.1557/PROC-452-761
中图分类号
T [工业技术];
学科分类号
08 ;
摘要
We show that the optical and electrical properties of microcrystalline silicon (mu c-Si:H) deposited by the VHF-GD technique at 110 MHz can considerably be tuned by changing the dilution ratio of silane to hydrogen. With increasing silane dilution we observe enhanced optical absorption for energies below 2 eV due to the transition of the material from amorphous/microcrystalline mixture to a pure microcrystalline phase. Simultaneously, the light scattering and the defect absorption increases. Strong dilution also promotes the incorporation of impurities into the material, leading to a pronounced extrinsic behaviour as seen from the decrease of the activiation energy of the electrical conductivity. The electrical properties were investigated in the dark by the Time of Flight technique. We measured drift mobilities at room temperature which slightly increase with dilution, reaching values of 3 cm(2)/Vs for electrons and 1.2 cm(2)/Vs for holes. The ratio between electron and hole drift mobilities is found to be around 2 for all samples studied, similar to that of crystalline silicon. Furthermore, post-transient Time of Flight measurements revealed detrimental electron deep traps in low dilution material.
引用
收藏
页码:761 / 766
页数:6
相关论文
empty
未找到相关数据