We fabricated TFPT with 14-nm-thick n-ZnO channel at 80°C by ALD technique. The drain to source photocurrent due to UV photons can be tuned by changing gate voltage. We also observed that the absorption of sub-bandgap photons could be prevented by operating at positive gate bias. This property could be used for light modulators for visible regime. Moreover, this could be applied to the smart glass technology for electrical voltage controlled transparency. Furthermore, solar-blind UV detectors could also be designed with this technology. © 2012 IEEE.