Light-induced metastability in pure and hydrogenated amorphous silicon

被引:3
|
作者
Queen, D. R. [1 ]
Liu, X. [2 ]
Karel, J. [3 ]
Wang, Q. [4 ]
Crandall, R. S. [4 ]
Metcalf, T. H. [2 ]
Hellman, F. [1 ]
机构
[1] Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA
[2] Naval Res Lab, Washington, DC 20375 USA
[3] Univ Calif Berkeley, Dept Mat Sci & Engn, Berkeley, CA 94720 USA
[4] Natl Renewable Energy Lab, Golden, CO 80401 USA
基金
美国国家科学基金会;
关键词
A-SI-H; LOW-ENERGY EXCITATIONS; THERMAL-CONDUCTIVITY; INTERNAL-FRICTION; DEVICE-QUALITY; THIN-FILMS; SOLIDS; HEAT; DEPOSITION; GLASSES;
D O I
10.1209/0295-5075/112/26001
中图分类号
O4 [物理学];
学科分类号
0702 ;
摘要
Light soaking is found to increase the specific heat C and internal friction Q(-1) of pure (a-Si) and hydrogenated (a-Si: H) amorphous silicon. At the lowest temperatures, the increases in C and Q(-1) are consistent with an increased density of two-level systems (TLS). The light-induced increase in C persists to room temperature. Neither the sound velocity nor shear modulus change with light soaking indicating that the Debye specific heat is unchanged which suggests that light soaking creates localized vibrational modes in addition to TLS. The increase can be reversibly added and removed by light soaking and annealing, respectively, suggesting that it is related to the Staebler-Wronski effect (SWE), even in a-Si without H, and involves a reversible nanoscale structural rearrangement that is facilitated by, but does not require, H to occur. Copyright (C) EPLA,
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页数:6
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