The acetone-sensing performance of BiFeO₃ is related to structural phase transformation, morphology and band gap energy which can be modulated by rare-earth ions doping. In this work, Bi_1−xEr_xFeO₃ nanoparticles with different amounts of Er doping were synthesized via the sol-gel method. The mechanism of Er doping on acetone-sensing performance of Bi_1−xEr_xFeO₃ (x = 0, 0.05, 0.1 and 0.2) sensors was the focus of the research. The optimal working temperature of Bi_0.9Er_0.1FeO₃ (300 °C) was decreased by 60 °C compared to BiFeO₃ (360 °C). The Bi_0.9Er_0.1FeO₃ sample demonstrated the optimal response to 100 ppm acetone (43.2), which was 4.8 times that of pure BFO at 300 °C. The primary reason, which enhances the acetone-sensing performance, could be the phase transformation induced by Er doping. The lattice distortions induced by phase transformation are favorable to increasing the carrier concentration and mobility, which will bring more changes to the hole-accumulation layer. Thus, the acetone-sensing performance of Bi_0.9Er_0.1FeO₃ was improved.

Graphene (G), TiO ₂ fusiform nanorods (TiO ₂ NRs) adsorbed with Au nanoparticles (AuNPs) are prepared and blended as multifunctional materials into TiO ₂ nanocrystalline film to form a novel ternary (G-TiO ₂ NRs-Au) composite photoanode in dye-sensitized solar cells (DSSCs). The effects of G-TiO ₂ NRs-Au on the properties of the photoanode and DSSC are investigated. Results show that, by blending G-TiO ₂ NRs-Au, the light absorption and scattering of the photoanode are obviously improved, and the charge transfer resistance R ₂ and electron recombination are decreased, resulting in a significant enhancement in the short-circuit current density ( J _sc ) and the photoelectric conversion efficiency (PCE) of the DSSCs. The maximum J _sc of 17.66 mA cm ⁻² and PCE of 8.56% are obtained in the optimal G-TiO ₂ NRs-Au-based DSSC, about 33.6% and 35.0% higher than that obtained in the conventional TiO ₂ -based DSSC. This significant improvement in the performance of the DSSC can be attributed to the ternary composite complementary effects of multi-functions from the surface plasmon resonance of AuNPs, light scattering of TiO ₂ NRs, and the improved dye loading and fast electron transmission channel from graphene. This study provides an effective way of ternary composite complementary enhancement of the J _sc and PCE of the DSSCs.

TiO ₂ microspheres (TMSs) with unique hierarchical structure and unusual high specific surface area are synthesized and incorporated into a photoanode in various TMS multilayer gradient architectures to form novel photoanodes and dye-sensitized solar cells (DSSCs). Significant influences of these architectures on the photoelectric properties of DSSCs are obtained. The DSSC with the optimal TMS gradient-ascent architecture of M036 has the largest amounts of dye absorption, strongest light absorption, longest electron lifetime and lowest electron recombination, and thus exhibits the maximum short circuit current density (J _sc ) of 16.49 mA cm ⁻² and photoelectric conversion efficiency ( η ) of 7.01%, notably higher than those of conventional DSSCs by 21% and 22%, respectively. These notable improvements in the properties of DSSCs can be attributed to the TMS gradient-ascent architecture of M036 which can most effectively increase dye absorption and localize incident light within the photoanode by the light scattering of TMSs, and thus utilize the incident light thoroughly. This study provides an optimized and universal configuration for the scattering microspheres incorporated in the hybrid photoanode, which can significantly improve the performance of DSSCs.

This study systematically investigated the effects of oxygen plasma treatment on oxygen vacancy defects in sputtered β-gallium oxide (β-Ga₂O₃) films and their corresponding ultraviolet (UV) detection performance. The sputtered β-Ga₂O₃ film subjected to 1 min of oxygen plasma treatment exhibited optimal photodetection properties. Compared to the untreated sample, the dark current was reduced by approximately one order of magnitude to 0.378 pA at 10 V bias. It exhibited an 86% (from 2.92 s to 0.41 s) decrease in response time, a 41.6% increase in photocurrent, a very high photo-to-dark current ratio of 9.18 × 10⁵, and a specific detectivity of 2.62 × 10¹⁰ cm·Hz^1/2W⁻¹ under 254 nm UV illumination intensity of 799 μW/cm² at 10 V bias. Notably, appropriate oxygen plasma treatment minimizes electron capture, enhances the separation and collection of photogenerated carriers, and suppresses the persistent photoconductivity (PPC) effect, thus ultimately shortening the response time. Oxygen plasma processing thus provides an effective approach to fabricating high-performance β-Ga₂O₃ solar-blind photodetectors (SBPDs).