Calcination induced phase transformation of TiO2 nanostructures and fabricated a Schottky diode as humidity sensor based on rutile phase

•High-quality rutile TiO2 NRs were grown on seeded Si substrates via CBD.•The anatase-rutile phase transformation took place at 550 °C.•A MSM type humidity sensor device was fabricated based on the optimal sample.

The effects of annealing treatment on growth of TiO2 nanostructures (Ns) on the structural and morphological properties were studied. The phase transformation also investigated in this study. TiO2 Ns were fabricated on p-type (111)-oriented silicon substrates. Chemical bath deposition (CBD) method was employed to grow TiO2 Ns on the Si substrate at different annealing temperatures (without annealing, 350, 550, 750, and 950 °C). The sample prepared at an annealing temperature of 550 °C had a high crystallinity. A metal-semiconductor-metal type humidity sensor device was fabricated by depositing Pt contacts on top of the optimal sample (the sample annealed at 550 °C) and the device working at room temperature, environmentally friendly features, and uncomplicated low-cost fabrication.

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