Optically Induced Localized Paramagnetic States in Amorphous Semiconductors

In addition to the previously reported paramagnetic hole center localized on the chalcogen, a conjugate optically induced electron center localized on an As atom is observed in glassy ${\mathrm{As}}_2$ ${\mathrm{S}}_3$ and ${\mathrm{As}}_2$ ${\mathrm{Se}}_3$. The chalcogen center is further identified as a hole localized in a nonbonding $p$ orbital. These optically induced centers are unique to the amorphous phase, and their density saturates at or below ${10}^{17}$ spins/${\mathrm{cm}}^3$.