Study of Radiative Defects Using Current-Voltage Characteristics in ZnO Rods Catalytically Grown on 4H-p-SiC

Abstract EN

High-quality ZnO rods were grown by the vapour-liquid-solid (VLS) technique on 4H-p-SiC substrate.

The current transport mechanisms of the diodes at room temperature (RT) have been explained in term of the space-charge-limited current model based on the energy band diagram of ZnO rods/4H-p-SiC heterostructure.

The tunneling mechanism via deep-level states was found to be the main conduction process at low-applied voltage but at trap-filled limit voltage VTFL all traps are filled and the space-charge-limited current conduction dominated the current transport.

From the RT current voltage measurements, the energy of the deep level trap and the trap concentration were obtained as ∼0.24±0.02 eV and 4.4×1018cm−3, respectively.

The deep level states observed correspond to zinc interstitial (Zni ), responsible for the violet emission.