A wide-band UV photodiode based on n-ZnO/p-Si heterojunctions

• Zinc oxide (ZnO) nanorods were prepared via low temperature hydrothermal process on a p-type silicon.
• The prepared heterojunction shows an excellent rectifier behavior with high break voltage.
• The prepared photodiode ZnO/p Si heterojunction shows interesting UV sensing properties with a visible blind behavior.
• The prepared photodiode shows a high repeatability with different UV light pulse duration that makes it suitable for optical switching applications.

We report on the fabrication of zinc oxide (ZnO) nanorods on p-type silicon (p-Si) photodiodes. The nanorods are prepared by low-temperature hydrothermal processing. The fabricated photodiodes exhibit an excellent rectifying ratio of 370 at 10 V. The responsivity to ultraviolet (UV) photons is stable at 0.29 A/W up to 300 nm, with a peak value of 0.38 A/W at 360 nm. Furthermore, the prepared photodiodes demonstrate visible blind behavior, indicating that ZnO nanorods grown on p-Si substrates can be used as UV photodiodes with visible blind responses.