As a promising third-generation semiconductor, gallium oxide (Ga₂O₃) is currently facing bottleneck for its p-type doping. The doping process of conventional semiconductors usually introduces trace impurities, which is a major technical problem in the electronics industry. In this article, we conceived that the process complexity could be significantly alleviated, and a high degree of control over the results could be attained using the selective enrichment of liquid metal interfaces and harvesting the doped metal oxide semiconductor layers. An appropriate mechanism is thus proposed to prepare the doped semiconducting based on multicomponent liquid metal alloys. Liquid metal alloys with the certain Cu weight ratios in bulk are utilized to harvest Cu-doped Ga₂O₃ films, which result in p-type conductivity. Then, field-effect transistors were integrated using the printed p and n-type Ga₂O₃ films and demonstrated to own excellent electrical properties and stability. Au electrodes fabricated on the printed Ga₂O₃ and Cu-doped Ga₂O₃ layers showed good Ohmic behavior. Furthermore, high-power diodes are realized using printed p and n-type Ga₂O₃ homojunction through combining van der Waals stacking with transfer printing. The fabricated Ga₂O₃ homojunction diode exhibited good efficiency at room temperature, involving a rectification ratio of 10³ and forward current density at 10 V ([email protected] V) of 1.3 mA. This opens the opportunity for the cost-effective creation of semiconductor films with controlled metal dopants. The process disclosed here suggests important strategies for further synthesis and manufacturing routes in electronics industries.

A gas-mediated fabrication of centimeter-scale two-dimensional (2D) semiconductors and ultraviolet photodetector by a liquid metal-based printing was reported. Various large-scale 2D materials (Ga₂O₃, In₂O₃, SnO) were demonstrated to be directly printed at ambient air on different substrates. Such printing represents a generic, fast, clean, and scalable technique to quickly manufacture 2D semiconductors. The electrical properties were explored to quantify the printed 2D films, which were somewhat deficient in previous studies. In particular, to explore and facilitate the advantages of this 2D semiconductor in functional electronic applications, strategies for realizing fully printed Ga₂O₃/Si heterojunction photodetector via low-temperature and low-cost processes were developed. The device exhibits excellent sensibility and rapid photoresponse times. This work offers feasible way to develop high-performance ultraviolet photodetector for mass production. It also suggests a promising direction for making large-scale 2D photoelectronic and electronic systems and is expected to be extensively useful in the coming time.

In the process of preparing CsPbBr₃ films by two-step or multi-step methods, due to the low solubility of CsBr in organic solvents, the prepared perovskite films often have a large number of holes, which is definitely not conducive to the performance of CsPbBr₃ perovskite solar cells (PSCs). In response to this problem, this article proposed a method of introducing InBr₃ into the PbBr₂ precursor to prepare a porous PbBr₂ film to increase the reaction efficiency between CsBr and PbBr₂ and achieve the purpose of In (Ⅲ) incorporation, which not only optimized the morphology of the produced CsPbBr₃ film but also enhanced the charge extraction and transport capabilities, which was ascribed to the reduction of the trap state density and impurity phases in the perovskite films, improving the performance of CsPbBr₃ PSCs. At the optimal InBr₃ concentration of 0.21 M, the InBr₃:CsPbBr₃ perovskite solar cell exhibited a power conversion efficiency of 6.48%, which was significantly higher than that of the pristine device.

UV detectors have the advantages of simple signal processing, low false alarm rate, and strong anti-interference capability, and are widely used in both defense and civil applications. Gallium oxide (Ga₂O₃) holds great promise for photodetection, but its slow response rate hinders practical applications, so fast-response alternatives are urgently needed. Here we demonstrated ultrathin quasi-two-dimensional (2D) Ga₂O₃ vertical UV photodetectors with short channel lengths constructed via liquid metal printing strategy for the first time. The device achieves ultrafast response time (≈1.18 μs), high detectivity (≈2.8 × 10¹³Jones), large switching ratio (~10⁷), and low dark current (≈10 pA), which is comparable to commercial materials, demonstrating its considerable capability for photodetection technology field. This high-performance and low-cost photodetector based on liquid metal printing process provides a successful start for a wide range of applications of Ga₂O₃ in UV detection. It demonstrates the great potential of novel quasi-2D Ga₂O₃ devices for next-generation photodetection technologies.