Rectifying properties of sol–gel synthesized Al:ZnO/Si (N–n) thin film heterojunctions

We report on the rectifying behavior of sol–gel synthesized Al (1 and 3at%):ZnO/Si (N–n) thin film isotype heterojunctions. The films were dense and uniform over the substrate and show polycrystalline morphology with defined grain boundaries. The current–voltage (I–V) characteristics of the junctions at room temperature and high temperature in air ambient were found to be asymmetric with an increase in rectification ratio (If/Ir) from 1.29 to 3.70 for 1at% and from 0.60 to 2.54 for 3at% of Al (at a bias voltage of 5V) for increase in temperature upto 150°C. The I–V characteristics of the junctions were explained on the basis of high temperature carrier injection and single carrier dynamics.