Thermally stimulated H emission and diffusion in hydrogenated amorphous silicon
arXiv:cond-mat/0611375 · doi:10.1209/0295-5075/79/36001
Abstract
We report first principles ab initio density functional calculations of hydrogen dynam- ics in hydrogenated amorphous silicon. Thermal motion of the host Si atoms drives H diffusion, as we demonstrate by direct simulation and explain with simple models. Si-Si bond centers and Si ring centers are local energy minima as expected. We also describe a new mechanism for break- ing Si-H bonds to release free atomic H into the network: a fluctuation bond center detachment (FBCD) assisted diffusion. H dynamics in a-Si:H is dominated by structural fluctuations intrinsic to the amorphous phase not present in the crystal.
arXiv comment4 pages, 5 figures, In press EPL (Jun. 2007)
References in corpus (6)
- The SIESTA method for ab initio order-N materials simulation
- Efficient index handling of multidimensional periodic boundary conditions
- High-quality continuous random networks
- Identification of relaxation and diffusion mechanisms in amorphous silicon
- Hydrogen dynamics and light-induced structural changes in hydrogenated amorphous silicon
- Diffusion of hydrogen in crystalline silicon