Numerical simulation and analysis of the dark and illuminated J-V characteristics of a-Si-H p-i-n diodes

Dark and illuminated current-voltage (J-V) characteristics of the hydrogenated amorphous silicon (a-Si:H) p-i-n diode have been simulated by solving numerically the full set of transport equations. The dependence of the dark current on the intrinsic layer (i-layer) thickness and on the measurement temperature is investigated by taking into account the presence of the p/i interface defect states. Good agreement with experimental data is obtained when the p/i interface defect density is increased with increasing i-layer thickness. Further, no appreciable influence was remarked for the i/n interface states on the J-V characteristic, which is in agreement with experimental observations. The numerical simulation also concerned the evaluation of the diode photo-parameters, i.e. the short-circuit current density (Jsc) and the open-circuit voltage (Voc), and reproduced, in a good manner, the light intensity dependence of Jsc and Voc for different i-layer thicknesses