Determination of the density of states in p-doped hydrogenated amorphous silicon by means of the modulated photocurrent experiment

Abstract

The density of states (DOS) of p-doped a-Si:H has been measured with the Modulated Photocurrent (MPC) technique for various concentrations of B 2H 6 and B(CH 3) 3 in the gas phase during the deposition. For both types of dopant the measured DOS exhibits a large increase with the concentration of dopant. However, the E 04 gap decreases when doping with B 2H 6 whereas it is almost unchanged when doping with B(CH 3) 3. The evolution with the concentration of p dopant of the DOS measured by the MPC technique is discussed in the light of models found in the literature.