The characterization of amorphous AZO-n/Si-p hetrojunction diode for solar cell application

The aim of the present study is to verify the effect of annealing temperature variation on zinc oxide doped with aluminum thin films deposited on p-type silicon substrates. Here, all thin films were annealed in nitrogen environment and its structural, electrical, and optical characterizations were investigated. The results of X ray diffraction patterns showed the amorphous structure of zinc oxide doped with aluminum thin films. Field Emission Scanning Electron Microscopes images illustrated the increase of grain size by increasing annealing temperature up to 500 °C. The reflectance analysis showed that for this annealing temperature, that the energy band gap of zinc oxide doped with aluminum thin film was moved to higher energy level. The electrical properties were investigated by Current–Voltage measurement carried out in the light at room temperatures. The short circuit current, ideality factor, saturation current, and open circuit voltage of the zinc oxide doped with aluminum on silicon heterojunction strongly depended on annealing conditions due to charge carrier trapping and density of defect on interface. By considering reverse current and forward current, the ratio of forward current to reverse current had the maximum value at 1 V which was belonged to n type zinc oxide doped with aluminum on p type silicon heterojunction at 500 °C annealing temperature.