Engineering of nanoparticles to detect ultraviolet light within a specified range and its feasibility to make a device has been demonstrated. It is shown that the absorption edge of a material can be shifted to significantly lower wavelengths in the UV range by using nanoparticles and that this feature can be incorporated within a device. All experimental work was focused on ZnO. Both commercially obtained ZnO nanoparticles as well as in-house synthesized ZnO nanoparticles were examined. For the in-house developed particles it was shown that varying the diameter of the ZnO nanoparticles could vary the absorption wavelength from 315 to 365 nm. Commercially available nanoparticles did not show this shift due to their relatively larger sizes (diameter ≅ 20 nm) as well as their broad size distributions.
A photocurrent effect of UV light on thin films prepared with nanoparticles has been demonstrated. Not only the optical band-gap value depends on the size of the nanoparticles but also the mobility gap of the material and, as a consequence, the onset of photocurrent.