Photodegradation Activity of Sputtered Indium Oxide and Suboxide Thin Films on Rhodamine-B Dye

The relationship between the oxygen composition of In₂O₃ thin films and their photodegradation capabilities has not been elucidated previously. In this investigation, the electronic and material characteristics of several In₂O₃ sputtered compositions were correlated with their rhodamine B dye degradation rates under white light. Furthermore, the base degradation rate of films with high indium content was enhanced by more than four times by preintroducing H₂O₂ as an oxidizing agent. X-ray photoelectron spectroscopy and Hall measurements indicate an increase in oxygen vacancy content and a corresponding ionizing effect. Cyclic voltammetry also shows a corresponding shift in its anodic peak from -2000 to -1500 mV. A 60% increase in degradation rates was observed with the use of black silicon as the substrate support, as well as improved absorption of visible light wavelengths. In addition, we have used the Supercell program for the first time to initialize suboxide structures that correlate with the measured X-ray diffraction peak positions, and the cavity size calculations agree with Hall mobility trends.