Modulated photoconductivity studies of a-$As_2S_e3 $ thin films

Özet

Modulated photocurrent measurements in amorphous arsenic triselenide (a-$As_2S_e3 $ ) is reported. Particular focus is paid towards photocarrier lifetimes as a function of temperature, and applied electric field (i.e. dc) were determined by using the quadrature frequency-resolved spectroscopy method. The activation energy from the photocurrent as a function of temperature was determined to be about 125 meV for a constant illumination intensity of 2.3 mW. Its value was found to be almost independent of the applied electric field. The exponent v in the power law relationship $(I_{ph} \alpha G^v)$ between generating flux and photocurrent was obtained under different electric fields. The electric field dependence of photocurrent at various temperatures was also measured. A very little non-ohmic contact behavior was observed at low fields and at high temperatures.