The modulated photocurrent of amorphous HgCdTe thin films

Amorphous HgCdTe thin films were deposited on quartz substrate by RF magnetron sputtering technique. The modulated photocurrent(MPC) of amorphous HgCdTe thin films has been investigated as a function of temperature T, the excitation light intensity F, and applied electric fields E-B. The results indicated that the modulated photocurrent show an activated behavior in the range of 80K-300K. The activated energy Delta E-ap of the modulated photocurrent was found to strongly depend on temperature, whereas it is nearly independent of the applied electric field. The exponent gamma in the power law relationship (I-p proportional to F-gamma) between excitation light intensity F and modulated photocurrent of amorphous HgCdTe thin films was obtained at different temperature. The gamma depends strongly on the temperature T, but it is independence of applied electric fields EB. The values of exponent gamma of amorphous HgCdTe thin films lie between 0.5 and 1.0. The results indicated a continuous distribution of localized states exists in amorphous HgCdTe thin films.