Effect of Nitrogen Gas Pressure on Properties of Sputtered Layer-based Au/ZnO/Si/Au Photodiode: Occurrence of p-type ZnO Semiconductor Material.

A photodiode based on zinc oxide is fabricated using a direct current DC sputtering system. The effect of the nitrogen (N) ratio to argon (Ar) on photoelectrical properties is investigated via current-voltage characteristics. The nitrogen is varied within the 0–100 cm3 range, while the argon is maintained constant during the deposition process. The Au/ZnO:N/nSi/Au photodiode exhibited a high rectification factor around 105. According to high obtained value of ideality factor n ~3 a non-ideal behavior of Au/ZnO:N/nSi/Au photodiode is revealed. Saturation current (Is) and barrier height (φB) are found to be around 1 nA and 0.84 eV, respectively. Besides, the series resistance of 100 Ω is calculated by Cheung method. The Au/ZnO:N/nSi/Au heterostructure exhibited a high photosensitivity of 104. The sputtered as-grown ZnO films on glass are characterized by SEM and EDX facilities. The grain sizes are found to be around 24 nm. [ABSTRACT FROM AUTHOR]