Experimental study and modeling of reverse-bias dark currents in PIN structures using amorphous and polymorphous silicon

The dark current generation mechanisms in PIN diodes were studied using amorphous and polymorphous silicon in intrinsic layer. The evolution of the dark current with increasing thickness of the intrinsic layer was found to be governed by field-enhanced thermal generation. It was observed that the field enhancement effect is considerably higher in thin diodes because of their higher electric fields. The results show that the high interface defect density is the limiting factor to the properties of thin PIN pm-Si:H diodes deposited at high pressure and high rf power by plasma enhanced chemical vapor deposition (PECVD).