Photosensitivity Characterization of Nanostructured Tin Oxide Films and Alternative Photodetector Application

In this paper, we present an analysis of the photosensitivity property of electrical resistance of nanostructured porous tin oxide films (SnO₂) deposited on Si substrates using a spray method. Based on this property, we propose a new application for this material as an element in a photodetector device. As we verified that the film photosensitivity is influenced by room temperature, to develop a photodetector device, we propose a microcontroller-based algorithm for compensating temperature changes in a certain range. The morphological and chemical structure of the sample films revealed by atomic force microscopy (AFM) and Raman spectroscopy are also discussed. The dynamics of the photodetector have been tested by varying the frequency of light excitation and the temperature of the film. The results show that the device works properly for intermediate ranges of frequency and temperature, but its response degrades as the frequency or temperature rises.