Spin-dependent processes in amorphous silicon-rich silicon-nitride

A study of spin-dependent charge carrier transitions in silicon-rich hydrogenated amorphous silicon-nitride (a-SiNx:H) p-i-n devices is presented. Pulsed electrically detected magnetic resonance allows us to determine the paramagnetic states that influence the photocurrent and provides insights into the nature of spin-coupling between charge carriers. We show that, in contrast to hydrogenated amorphous silicon, a-SiNx:H allows strongly spin-coupled, correlated (geminate) pairs of charge carriers to dissociate into nongeminate pairs that contribute to the photocurrent. This is discussed with regard to the application of a-SiNx:H as a photoelectrochemical electrode material.