Bound-exciton-induced current bistability in a silicon light-emitting diode

A bound-exciton-induced current bistability is observed under forward bias in an efficient silicon light-emitting diode at low temperatures. Two stable states of the S-type differential conductivity correspond to empty and filled states of bound excitons, respectively. The relationship between the current–voltage characteristic and the bound-exciton population can be accounted for using a rate equation model for bound and free excitons. The consistency between the theoretical and experimental results indicates that bound excitons, despite their neutral-charged states, contribute to the current bistability in silicon $p–n$ junction diodes.