The effect of chlorine doping on photostructural defect states in amorphous selenium films (∼100 &mgr;m) has been studied using the thermally stimulated discharge current technique. Chlorine doping in amorphous selenium results in the shift of deep photostructural defect states C+3and C−1to relatively shallower levels, i.e., from 1.6 and 1.7 eV in pure films to 1.4 and 1.5 eV in chlorine‐doped films for electrons and holes, respectively. These effects have been explained in terms of the enhancement in the conductivity of amorphous selenium and increase in the mobility of electrons and holes on chlorine doping.