Published online by Cambridge University Press: 15 February 2011
We propose a new metastable defect associated with hydrogen atoms in amorphous silicon. A higher energy metastable state is formed when H is flipped to the backside of the Si-H bond at monohydride sites. This defect is described by a double-well potential energy and occurs in addition to metastable dangling bonds. The dipole moment of this “H-flip” defect is larger and increases the infrared absorption. This defect accounts for large structural changes observed on light soaking including larger absorption and volume dilation.