Photosensitivity n-channel ZnO phototransistor for optoelectronic applications: Modeling of ZnO TFT

The zinc oxide semiconductor thin film transistor was fabricated on a SiO2/Si substrate by sol gel method. The ZnO film is consisted of nanofibers with the changing diameter along the fibers. Electrical characteristics of the zinc oxide transistor under dark and white light illuminations were analyzed. The mobility value of the ZnO TFT was found to be 1.86 × 10−2 cm2/V s. The ZnO thin film transistor works in an n-channel operational mode because the drain current increases with the positive gate voltages. A significant increase in the drain current of ZnO TFT is observed with a maximum photosensitivity of 100 under visible light illumination. It is concluded that the ZnO thin film transistor can be used in visible photo-detecting device applications.

The ZnO thin film transistor shows a maximum photosensitivity of 100 under visible light illumination and the transistor follows the photovoltaic effect in the device turn-on state. The output characteristics of ZnO TFT were modeled and the obtained results are in good agreement with the experimental results. It is concluded that the ZnO-based TFT can be used as a promising white light photo-detecting device for optoelectronic applications.Figure optionsDownload as PowerPoint slideHighlights
► The zinc oxide thin film transistor was fabricated by sol gel method.
► ZnO thin film transistor has the photosensitivity of 100.
► The transistor can be used in visible photo-detecting device applications.