Electrical Properties of Silver Photodoped Amorphous Red Phosphorus

Abstract

Effects of photodoping and thermal doping of silver into sputtered amorphous red phosphorus films (a-P_red) on the electrical properties are studied. The d. c. efectrical conductivity of the photodoped a-p_red at room temperature is about 1×10^?5 Scm^?1 which is a very high value comparing with that of the undoped a-p_red (1×10^?14 Scm^?1). The activation energy for the conduction of the photodoped a-P_red is lower than that of the a-p^red. In contrast, the activation energy of the thermally doped a-p_red is essentially the same as that of the undoped a-p_red. SEM-EDX analyses show that colloidal silver was deposited in the thermally doped a-p_red but not in the photodoped a-p_red. It seems that the photo-doping involves the ionization process of silver by illumination, i.e., Ag^o → Ag⁺ + e^?.