RESISTIVITY CHANGE IN SrTiO3 UPON IRRADIATION AND ITS APPLICATION IN LIGHT SENSING
Keywords:
Strontium titanate (SrTiO3), light sensing, irradiation effect, oxygen vacancyAbstract
Commercial light sensing devices are usually made of semiconducting materials which have small band gaps (e.g. CdSe, CdS) and hence they are opaque under visible light. In this study, the focused material is transparent strontium titanate (SrTiO3) which has a larger band gap (around 3.2-3.3 eV). The resistivity changes under various types of irradiation at ambient pressure were investigated, by using a sputtering technique for making gold electrodes on SrTiO3 samples. It was found that the resistance of insulating SrTiO3 single crystals could decrease dramatically upon exposure to violet-to-ultraviolet (UV) light sources which were the deuterium lamp and UV light emitting diode (LED) used in our case. The response time of the resistivity change was also investigated. The results suggest that SrTiO3 has the potential usage as a transparent sensor which is responsive in the violet-to-ultraviolet range.
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