A new type of self-powered solar-blind photoelectrochemical-type photodetector based on 3D a-Ga₂O₃/CFP core–shell structures was obtained. The device is simple, low cost, and has high reproducibility, and extreme stability.

Solar-blind deep-ultraviolet photodetectors are one of the most effective tools to detect corona discharge because high-voltage corona discharge is always accompanied by deep-ultraviolet light (UVC, 200–280 nm), referred to as solar-blind signals. In this study, a fully transparent metal-semiconductor-metal solar-blind photodetector with Al-doped ZnO (AZO) transparent electrodes was successfully constructed based on amorphous Ga₂O₃ film (a-Ga₂O₃) and prepared by radio frequency magnetron sputtering. The as-fabricated fully transparent device exhibits excellent performance, including an ultra-low dark current of 2.84 pA, a high photo-to-dark current ratio of 1.41 × 10⁷, superb rejection ratio (R₂₅₄/R₄₀₀ = 2.93 × 10⁵), a large responsivity of 2.66 A W⁻¹, superb detectivity (4.84 × 10¹⁴ Jones), and fast response speed (rise/fall time: 24 μs/1.24 ms). It is worth noting that the fully transparent a-Ga₂O₃ photodetector demonstrates ultra-high sensitivity to weak solar-blind signals, far below the 100 nW cm⁻² threshold of the test equipment. It also has high-resolution detection capabilities for subtle changes in radiation intensity. Acting as a sensor for the high-voltage corona discharge simulation detection system, the fully transparent a-Ga₂O₃ photodetector can clearly detect extremely weak solar-blind signals. The results described in this work serve as proof-of-concept for future applications of amorphous Ga₂O₃ solar-blind deep-ultraviolet photodetectors in high-voltage corona discharge detection.

One of the most important applications of photodetectors is as sensing units in imaging systems. In practical applications, a photodetector array with high uniformity and high performance is an indispensable part of the imaging system. Herein, a photodetector array (5 × 4) consisting of 20 photodetector units, in which the photosensitive layer involves preprocessing commercial ε-Ga₂O₃ films with high temperature annealing, have been constructed by low-cost magnetron sputtering and mask processes. The ε-Ga₂O₃ ultraviolet photodetector unit shows excellent responsivity and detectivity of 6.18 A/W and 5 × 10¹³ Jones, respectively, an ultra-high light-to-dark ratio of 1.45 × 10⁵, and a fast photoresponse speed (0.14/0.09 s). At the same time, the device also shows good solar-blind characteristics and stability. Based on this, we demonstrate an ε-Ga₂O₃-thin-film-based solar-blind ultraviolet detector array with high uniformity and high performance for solar-blind imaging in optoelectronic integration applications.

Transparent conductive oxide (TCO) films are crucial in optoelectronic devices, such as photodetectors, due to their unique blend of transparency and electrical conductivity. ZnO is a top choice for TCOs owing to its excellent properties, non-toxicity, and cost-effectiveness. In this work, we explore the potential of carbon doping to enhance the electrical properties of ZnO films for transparent conductive applications. Our findings reveal that C-doped ZnO (ZnO:C) films retain the pristine high quality and surface morphology despite an increase in defects with higher C doping. Notably, C doping does not compromise the visible light transmittance of ZnO films, while inducing a gradual increase in optical bandgap, indicative of the typical Burstein–Moss effect. As carbon doping increases, the ZnO:C films exhibit improved carrier concentration, lower resistivity, and sustained high mobility, achieving optimal performance with an electron concentration of 3.73 × 1019 cm−3, resistivity of 3.69 × 10−3 Ω cm, and mobility of 46.08 cm2 V−1 s−1. Finally, we utilized ZnO:C films as a transparent electrode material in ε-Ga2O3-based photodetector, achieving the development of transparent device and attaining high-performance solar-blind detection capabilities. This work provides a strategy for developing a transparent conductive oxide, with ZnO:C emerging as a promising rival to IIIA-doped ZnO for optoelectronic applications.

In this paper, α-Ga₂O₃ nanorod arrays (NRAs) with preferential growth along the (110) direction were successfully prepared on the FTO substrate by the water bath method. With the help of a scanning electron microscope (SEM), X-ray diffractometer (XRD), and Raman spectrometer (Raman), the crystal structure and morphology characteristics of α-Ga₂O₃ NRAs were studied. On this basis, a photoelectrochemical (PEC) solar-blind ultraviolet photodetector based on the α-Ga₂O₃ NRAs was fabricated, and the photoelectric performance of the device was analyzed in detail through the PEC test system, and the working mechanism of the device was further discussed. The results show that the prepared α-Ga₂O₃ NRAs have good crystal quality which is closely arranged on the substrate and a quadrangular prism shape from the top view. The constructed α-Ga₂O₃ NRAs PEC photodetector shows typical solar-blind ultraviolet response characteristics and stable self-powered ability. Meanwhile, the device exhibited a high photo-dark current ratio (PDCR), responsivity (R) and detectivity (D*) of 1.01×10³, 11.34 mA/W and 2.68×10¹¹ Jones, respectively, as well as superior wavelength selectivity and fast response. This work confirms that α-Ga₂O₃ NRAs prepared by the water bath method have potential application prospects in highly sensitive and fast response PEC self-powered solar-blind ultraviolet photodetectors.

Underwater imaging technologies are increasingly crucial for environmental monitoring and resource exploration. However, the development of advanced photodetectors for such applications faces significant challenges, including interference from ambient visible and infrared light, adaptation to underwater environments, and cost‐effectiveness. Photoelectrochemical‐type solar‐blind photodetectors (PEC‐SBPDs) based on wide bandgap semiconductors have shown great promise in overcoming these challenges. Here, a novel approach to enhance the performance of α‐Ga₂O₃‐based PEC‐SBPDs is presented for underwater imaging through Mg‐doping. By employing a low‐cost hydrothermal synthesis technique, Mg‐doped α‐Ga₂O₃ nanorod arrays are fabricated, which induces the formation of V_O‐Mg_Ga complexes that enhances the interfacial catalytic activity and improves the transport of photogenerated carriers. The optimized PEC‐SBPDs exhibits a remarkable 435% increase in photocurrent response compared to undoped α‐Ga₂O₃, with a peak responsivity of 34.54 mA W⁻¹. A 5 × 5 PEC‐SBPD array based on Mg‐doped α‐Ga₂O₃ nanorods is successfully demonstrated for underwater solar‐blind imaging, achieving clear and efficient imaging in challenging underwater conditions. This study not only highlights the superior performance of Mg‐doped α‐Ga₂O₃ in underwater environments but also opens new avenues for the development of high‐performance self‐powered photodetectors in imaging, sensing, and other related applications.