Characterization of CdZnO/Si heterojunction photodiode prepared by pulsed laser deposition

The CdxZn1-xO thin films have been deposited on glass and Si substrates at room-temperature with different Cd contents (x = 0, 2%, 4% and 6 wt.%) by pulsed laser deposition (PLD) technique. X-ray diffraction (XRD) analyses evidenced that the films possess polycrystalline and a hexagonal ZnO crystal structure for x = 0, 2% and 4% with a preferred orientation in the a-axis (101) direction, while films with a mixed hexagonal and cubic structure was revealed for x = 6 wt.%. Electrical measurement presented that the resistivity decreased with increased temperature and concentration of Cd. The deliberated activation energy was reduced was from 0.224 to 0.113 eV with increase doping concentration. Current-voltage (I-V) and capacitance-voltage (C-V) characteristics of the fabricated CdxZn1-xO/p-Si heterojunction varied with the applied bias and the Cd concentration. The results of the values of built-in potential (V-bi) and the ideality factor (n) increased with raising Cd concentration.