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A low‐cost, high‐efficiency corona discharge detection method is important in ensuring the safety of high‐voltage transmission systems. High‐sensitivity solar‐blind deep‐ultraviolet (SBDU) photodetectors (PD) have obvious advantages in corona discharge detection. Herein, a fully transparent SBDU photoconductive detector with indium tin oxide (ITO) transparent electrodes is successfully constructed based on amorphous Ga2O3 (a‐Ga2O3) thin films. The device demonstrates an ultra‐high responsivity of 1.3 × 104 A W−1, a detectivity of 3.2 × 1014 Jones, and an external quantum efficiency of 6.7 × 106%. In addition, the capability of the ultra‐sensitive fully transparent photoconductive detector is investigated in terms of corona discharge detection. It is established that the device detection distance limit for simulated corona discharge detection is up to 70 cm, that is, the device can effectively detect extremely weak solar‐blind deep‐ultraviolet signals below 204 pW cm−2. A proof‐of‐concept for the future application of easily‐integrated fully transparent amorphous Ga2O3 photoconductive detectors with low manufacturing costs in high‐voltage corona discharge detection is provided. [ABSTRACT FROM AUTHOR]

The development of flexible electronics for detecting solar‐blind deep ultraviolet (UV‐C) light holds great promise for emerging technologies. Here, flexible photoelectrochemical photodetectors (PEC‐PDs) are demonstrated for self‐powered solar‐blind UV‐C sensing based on one‐step radio frequency sputtered amorphous gallium oxide (a‐Ga2O3) thin films on indium tin oxide‐coated polyethylene naphthalate (ITO/PEN) substrates in a simple and low‐cost manner. Surface functionalization of the ITO/PEN substrates with silver nanowires (Ag NWs) successfully embedded within the a‐Ga2O3 films significantly enhances the optoelectronic performance. Incorporating Ag NWs reduces charge transfer resistance and potential barrier, while enhancing built‐in electric field at the Ag NWs/a‐Ga2O3 interface, synergistically facilitating efficient electron transport. Consequently, the Ag NW‐modified PEC‐PDs exhibit approximately two‐fold increases in key metrics including responsivity (11.23 mA W−1) and response times (0.07/0.09 s rise/decay) under 254 nm illumination compared to pristine devices. Moreover, the Ag NW‐functionalized PEC‐PDs demonstrate superb mechanical flexibility and fatigue durability, maintaining ≈95% of the initial photoresponse current and responsivity after 500 bending cycles. This work provides valuable insights into designing high‐performance flexible self‐powered PEC‐PDs through ingenious photoanode engineering. [ABSTRACT FROM AUTHOR]

The construction of heterojunctions has attracted considerable attention among the various strategies of water-splitting for hydrogen evolution due to their band structure advantages. In this research, we combined chemical vapor deposition and pulsed laser deposition to fabricate MoS2/g-C3N4 heterojunction films on indium-tin oxide glass substrates, and we studied the photoelectrochemical (PEC) performance. The x-ray diffraction, x-ray photoelectron spectroscopy (XPS), and scanning electron microscope characterizations suggested the successful preparation of MoS2/g-C3N4 heterojunction films. In particular, the shifts of the peak positions in the XPS spectra indicated the formation of a strong interaction between the g-C3N4 and MoS2 films. After depositing MoS2 on the g-C3N4 film, the visible-light absorption was enhanced and broadened, the electrical conductivity improved, and the intensity of the photoluminescence peak decreased. As a result, the greater generation, faster transport, and lower recombination rate of electrons and holes caused the heterojunction films to show higher PEC performance. More importantly, the obtained MoS2/g-C3N4 film was confirmed to be an n–n type heterojunction and to have a typical type-II band structure, which could indeed suppress the recombination and promote the separation, transfer, and transport of photogenerated electron–holes. Finally, the obtained MoS2/g-C3N4 film successfully achieved the overall water-splitting and the H2 evolution rate when the visible-light radiation reached 252 µmol/h. [ABSTRACT FROM AUTHOR]

Solar-blind imaging has attracted considerable interest in both military and civilian applications, spurring the development of high-performance deep-ultraviolet photodetector arrays (PDAs) with wide-bandgap semiconductor materials. Herein, we present a novel method to enhance the performance of solar-blind PDAs (SBPDs) using β-Ga2O3 films obtained by the phase transition of heterogeneous epitaxial sub-stable ε-Ga2O3, achieved through high-temperature rapid annealing. Metal-semiconductor-metal-type SBPDs based on phase-transformed β-Ga2O3 films exhibited superior performance, including an ultrahigh responsivity of 459.38 A/W, detectivity of 1014−1015 Jones, external quantum efficiency of 104%−105%, rejection ratio (R254/R365) of 105−106, photo-to-dark current ratio of 104−106, fast response speed of 1.01 s/0.06 s, and favorable stability. Notably, the ultrahigh responsivity of β-Ga2O3-film-based devices was approximately 222-fold higher than that of ε-Ga2O3 film-based devices. The assembled 4 × 5 β-Ga2O3 film-based PDAs exhibited favorable uniformity, repeatability, and high spatial resolution for solar-blind imaging. Our study offers a promising approach for the development of high-performance β-Ga2O3-based PDAs for solar-blind ultraviolet imaging with potential applications in both military and civilian fields. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

In recent years, transparent electrode materials have had a positive effect on improving the responsivity of photodetectors by increasing the effective illumination area of devices due to their high transmittance. In this work, by using radio frequency magnetron sputtering and simple mask technology, an amorphous Ga2O3-based solar-blind UV photodetector with graphitic carbon (C) electrodes was created. The device exhibits a high responsivity of 16.34 A/W, an external quantum efficiency of 7979%, and excellent detectivity of 1.19 × 1013 Jones at room temperature under a light density of 5 μw/cm2. It has been proved that C electrodes can replace the traditional noble metal electrode. Additionally, the potential of the transparent photodetector array in solar-blind imaging is explored. We believe that the present study will pave the way for the preparation of a fully transparent and high-response solar-blind ultraviolet photodetector array. [ABSTRACT FROM AUTHOR]

Gallium oxide-based photoelectrochemical photodetectors (PEC-PDs) have received extensive attention for their natural self-powered characteristic and detection capability in solar-blind region. In this work, ZnO nanoparticles decorated α-Ga2O3 nanorods heterojunction (α-Ga2O3-ZnO) are synthesized on FTO conductive glass substrates as photoanodes for PEC-PDs. The efficient regulation of performance for α-Ga2O3-ZnO heterojunction PEC-PDs is achieved by varying the ZnO nanoparticles concentration. Experimental results show that all devices exhibit self-powered solar blind detection characteristics and the performance of ZnO nanoparticles decorated devices are all better than that of pristine α-Ga2O3. When the concentration of ZnO nanoparticles reaches to a certain value, the responsivity attains the maximum value as high as 34.2 mA/W, and the response time is as low as 0.25/0.18 s. Combined with first-principles calculations, the mechanism of the improved performance is discussed in detail. The results reveal that that the contact between α-Ga2O3 and ZnO can induce charges transfer, which constitutes a built-in electric field that acts as a driving force to separate the photogenerated carriers into different sections. This process can effectively prevent the recombination of photogenerated carriers and prolong the lifetime of e––h+, thus improve the overall detection performance finally. This work will provide meaningful guidance for the development of novel high-performance self-powered solar-blind deep-UV photodetectors. [ABSTRACT FROM AUTHOR]

Gallium oxide (Ga2O3) has been extensively studied recently because it is a natural candidate material for next generation solar-blind deep ultraviolet photodetectors (PDs). In this study, three dimensional (3D) amorphous Ga2O3 films (a-Ga2O3) were grown on carbon fibre paper (CFP) using a facile one-pot sputtering method. The prepared a-Ga2O3/CFP core–shell composites were used as photoanode materials for a new type of solar-blind photoelectrochemical (PEC)-type photodetector. By constructing a solid/liquid heterojunction, the resulting built-in electric field can separate electron–hole pairs effectively, facilitating a self-powering ability in this PEC-type photodetector. The device exhibited a maximum responsivity of approximately 12.90 mA W−1 and a rapid photoresponse time of around 0.15/0.13 s without external bias potential. Additionally, the PEC-type photodetector demonstrated outstanding stability after significant usage over a one-year period. The excellent performance of the fabricated a-Ga2O3/CFP core–shell photoanode, for self-powered PEC-type photodetectors, is extremely promising in the field of solar-blind photoelectric detection. [ABSTRACT FROM AUTHOR]

With applications in high performance electronics, photovoltaics, and catalysis, two-dimensional (2D) transition metal dichalcogenides (TMDCs) attract extensive attention due to their extraordinary physical properties. People have focused on TMDC-based materials for years, while the low mobility greatly hinders their further application. TMDC-based heterostructures with tunable band alignment have been experimentally confirmed to be feasible for photoelectronic devices or photocatalysts. Based on the density functional theory (DFT), there are four discoveries in this work: (1) we propose two new heterostructures based on BSe and MoS2/WS2 that have quite low mismatches and intrinsic type-II alignments. (2) Even though the VBM of BSe–MoS2 are completely contributed by BSe, the heterostructure is still endowed with a lower effective mass and a better transport characteristic in comparison with pristine structures. (3) A promoted absorption ability and a better transport characteristic oppose each other and the two characteristics cannot be obtained at the same time. (4) Tension strained structures can induce promoted light absorption in the solar spectrum and the predicted efficiency of the BSe–MoS2 bilayer can be as high as ∼19.3%, when the external electric field is applied. This theoretical survey proves that BSe–MoS2/WS2 with high flexibility and tunability are potential candidates for novel electronic devices and photocatalysts. [ABSTRACT FROM AUTHOR]