Metastability in amorphous silicon from hydrogen flips

A new metastability of hydrogen atoms in a-Si:H was found, from molecular dynamics simulations. In the higher energy configuration H is flipped to the backside of the SiH bond, and is bonded to the same silicon atom since the SiH bond is rotated by nearly 180°. This H-flip defect explains structural changes found from infrared absorption, volume dilation, and nuclear magnetic reasonance measurements.