In this study, pH sensors were successfully fabricated on a fluorine-doped tin oxide substrate and grown via hydrothermal methods for 8 h for pH sensing characteristics. The morphology was obtained by high-resolution scanning electron microscopy and showed randomly oriented flower-like nanostructures. The TiO₂ nanoflower pH sensors were measured over a pH range of 2–12. Results showed a high sensitivity of the TiO₂ nano-flowers pH sensor, 2.7 (μA)^1/2/pH, and a linear relationship between I_DS and pH (regression of 0.9991). The relationship between voltage reference and pH displayed a sensitivity of a 46 mV/pH and a linear regression of 0.9989. The experimental result indicated that a flower-like TiO₂ nanostructure extended gate field effect transistor (EGFET) pH sensor effectively detected the pH value.

In this paper, amorphous indium-gallium-oxide solar-blind metal-semiconductor-metal photodetectors were fabricated by using co-sputtering method. Three samples with different oxygen concentrations, namely, sample A without oxygen, sample B with 2% oxygen concentration, and sample C with 4% oxygen concentration, were investigated. The applied bias was 5 V during device characterization. The ultraviolet (UV)-to-visible rejection ratios were 39, 9.9 x 10³, and 1.1 x 10⁷ for samples A, B, and C, respectively. The dynamic responses of the decay times were 5.79/52.12 s, 1.96/30.49 s, and 0.02/0.75 s for samples A, B, and C, respectively. In summary, the 4% oxygen concentration sample exhibited excellent UV-to-visible rejection ratio and superior decay time.

The amorphous indium gallium oxide thin film transistor was fabricated using a cosputtering method. Two samples with different gate dielectric layers were used as follows: sample A with a SiO₂ dielectric layer; and sample B with an Al₂O₃ dielectric layer. The influence of the gate dielectrics on the electric and photo performance has been investigated. Atomic layer deposition deposited the dense film with low interface trapping density and effectively increased drain current. Therefore, sample B exhibited optimal parameters, with an I_on/I_off ratio of 7.39 × 10⁷, the subthreshold swing of 0.096 V dec⁻¹, and μ_FE of 5.36 cm² V⁻¹ s⁻¹. For ultraviolet (UV) detection, the UV-to-visible rejection ratio of the device was 3 × 10⁵, and the photoresponsivity was 0.38 A W⁻¹ at the V_GS of −5 V.

In this study, amorphous indium gallium oxide thin-film transistors (IGO TFTs) were fabricated by co-sputtering. Three samples with different deposition powers of the In₂O₃ target, namely, sample A with 50 W deposition power, sample B with 60 W deposition power, and sample C with 70 W deposition power, were investigated. The device performance revealed that oxygen vacancies are strongly dependent on indium content. However, when the deposition power of the In₂O₃ target increased, the number of oxygen vacancies, which act as charge carriers to improve the device performance, increased. The best performance was recorded at a threshold voltage of 1.1 V, on-off current ratio of 4.5 × 10⁶, and subthreshold swing of 3.82 V/dec in sample B. Meanwhile, the optical properties of sample B included a responsivity of 0.16 A/W and excellent ultraviolet-to-visible rejection ratio of 8 × 10⁴. IGO TFTs may act as photodetectors according to the results obtained for optical properties.

In this study, the electrically driven perovskite light-emitting diodes (PeLEDs) were investigated by hybridizing the organic polyethylene oxide, 1,3,5-tris (N-phenylbenzimiazole-2-yl) benzene (TPBi), and bis(3,5-difluoro-2-(2-pyridyl)phenyl-(2-carboxypyridyl) iridium III (FIrpic) with CsPbBr₃ in the emission layer and adopting the colloidal NiO_x nanoparticle (NP) hole transport layer. The synthesized NiO_x NPs, having an average size of ~5 nm, can be spin-coated to become a smooth and close-packed film on the indium–tin–oxide anode. The NiO_x NP layer possesses an overall transmittance of ~80% at 520 nm, which is about the peak position of electroluminescence (EL) spectra of CsPbBr₃ emission layer. The coating procedures of NiO_x NP and CsPbBr₃ layers were carried out in ambient air. The novel PeLED turned on at 2.4 V and emitted bright EL of 4456 cd/m² at 7 V, indicating the remarkable nonradiative-related defect elimination by organic additive addition and significant charge balance achieved by the NiO_x NP layer.