Optical-bias effect on transient electron-drift measurements in a -Si:H: Implications on the distribution and capture cross sections of the dangling bonds

The previously reported enhancement of the transient electron-drift signal in hydrogenated amorphous silicon under increasing optical bias, along with the puzzling independence from optical bias of the density of neutral dangling bonds at room temperature, are explained without the need of introducing ad hoc slow-relaxation phenomena. Implications on the energy distribution of the dangling bonds and on their capture cross sections are given.