Effect of Temperature on the Electrical Characteristics of Nanostructured n-ZnO/p-Si Heterojunction Diode

This paper describes temperature dependent electrical behavior of n-ZnO/p-Si heterojunction diode.Nanostructured Zinc Oxide (ZnO) thin film was deposited on p-type Silicon (Si) substrate by thermal evaporation technique for fabricating n-ZnO/p-Si heterojunction. XRD results revealed that grown ZnO nanoneedles on p-Si substrate are single crystalline with a hexagonal wurtzite structure. The temperature dependent electrical junction properties were investigated by current–voltage–temperature (I–V–T) measurement. The n-ZnO/p-Si junction exhibits strong rectifying behavior with a rectification ratio (forward current/reverse current) of ∼10². It is further confirmed that the fabricated p–n heterojunction showed an excellent stability over the temperature range of 15–120 °C. Temperature-dependent forward current measurement suggests that trap-assisted multistep tunneling is the dominant carrier transport mechanism in this p–n heterojunction. These results demonstrate the suitability of thermally deposited nanostructure ZnO thin film on Si substrate for fabrication of efficient and low-cost optoelectronic devices for Si-based integrated circuits.