Characterization of ZnO GaAs heterojunction

الملخص EN

Thin films of ZnO are prepared by pulse laser deposition.

These films were deposited on GaAs substrate to form heterojunction ZnO/GaAs solar cell.

The effect of annealing temperatures at (RT, 373, 473) K on properties of structural and optical of ZnO thin films has been studied.

The Diffraction analysis by X-ray indicated that all films have hexagonal polycrystalline structure.

AFM shows that the grains uniformly distributed with homogeneous structure.

The optical absorption spectra showed that all films have direct energy gap.

The band gap energy of these films decreased with increasing annealing temperatures.

From the electrical properties, the carriers have n-type conductivity.

From C-V measurement of ZnO/GaAs heterojunciton at frequency 100, 200 kHz, It is found that built–in potential (Vbi) increases with increased frequency.

As well as, from I-V characteristic it is observed that the ideality factor is 2.7.

Short-circuit current (Isc) is 4.0 mA/cm2, open circuit voltage is 0.5 V, fill factor is 0.7 and the efficiency is about 6.0 %.