An Alternative Scalable Process for the Synthesis of 4,6-Dichloropyrimidine-5-carbonitrile

A robust, safe, and scalable process for the synthesis of 4,6-dichloropyrimidine-5-carbonitrile is described. All of the intermediates in the process are storable under normal conditions. Significant process safety evaluation was undertaken in this route, and the highlights of these studies are presented. This scalable and safe synthetic strategy can be applied for multikilogram-scale production

Observation of Moiré Patterns in Twisted Stacks of Bilayer Perovskite Oxide Nanomembranes with Various Lattice Symmetries

The design and fabrication of novel quantum devices in which exotic phenomena arise from moiré physics have sparked a new race of conceptualization and creation of artificial lattice structures. This interest is further extended to the research on thin-film transition metal oxides, with the goal of synthesizing twisted layers of perovskite oxides concurrently revealing moiré landscapes. By utilizing a sacrificial-layer-based approach, we show that such high-quality twisted bilayer oxide nanomembrane structures can be achieved. We observe atomic-scale distinct moiré patterns directly formed with different twist angles, and the symmetry-inequivalent nanomembranes can be stacked together to constitute new complex moiré configurations. This study paves the way to the construction of higher-order artificial oxide heterostructures based on different materials/symmetries and provides the materials foundation for investigating moiré-related electronic effects in an expanded selection of twisted oxide thin films

Applications of Raman Spectroscopy in Clinical Medicine

Raman spectroscopy provides spectral information related to the specific molecular structures of substances and has been well established as a powerful tool for studying biological tissues and diagnosing diseases. This article reviews recent advances in Raman spectroscopy and its applications in diagnosing various critical diseases, including cancers, infections, and neurodegenerative diseases, and in predicting surgical outcomes. These advances are explored through discussion of state-of-the-art forms of Raman spectroscopy, such as surface-enhanced Raman spectroscopy, resonance Raman spectroscopy, and tip-enhanced Raman spectroscopy employed in biomedical sciences. We discuss biomedical applications, including various aspects and methods of ex vivo and in vivo medical diagnosis, sample collection, data processing, and achievements in realizing the correlation between Raman spectra and biochemical information in certain diseases. Finally, we present the limitations of the current study and provide perspectives for future research

Ultrasensitive, Superhigh Signal-to-Noise Ratio, Self-Powered Solar-Blind Photodetector Based on <i>n</i>‑Ga₂O₃/<i>p</i>‑CuSCN Core–Shell Microwire Heterojunction

Solar-blind photodetectors have captured intense attention due to their high significance in ultraviolet astronomy and biological detection. However, most of the solar-blind photodetectors have not shown extraordinary advantages in weak light signal detection because the forewarning of low-dose deep-ultraviolet radiation is so important for the human immune system. In this study, a high-performance solar-blind photodetector is constructed based on the n-Ga2O3/p-CuSCN core–shell microwire heterojunction by a simple immersion method. In comparison with the single device of the Ga2O3 and CuSCN, the heterojunction photodetector demonstrates an enhanced photoelectric performance with an ultralow dark current of 1.03 pA, high photo-to-dark current ratio of 4.14 × 104, and high rejection ratio (R254/R365) of 1.15 × 104 under a bias of 5 V. Excitingly, the heterostructure photodetector shows high sensitivity to the weak signal (1.5 μW/cm2) of deep ultraviolet and high-resolution detection to the subtle change of signal intensity (1.0 μW/cm2). Under the illumination with 254 nm light at 5 V, the photodetector shows a large responsivity of 13.3 mA/W, superb detectivity of 9.43 × 1011 Jones, and fast response speed with a rise time of 62 ms and decay time of 35 ms. Additionally, the photodetector can work without an external power supply and has specific solar-blind spectrum selectivity as well as excellent stability even through 1 month of storage. Such prominent photodetection, profited by the novel geometric construction and the built-in electric field originating from the p–n heterojunction, meets greatly well the “5S” requirements of the photodetector for practical application

Supplementary document for Control of upconversion luminescence by tailoring energy migration in doped perovskite superlattices - 5668461.pdf

Supplementary Materia

Supplementary document for Mechanically-induced enhancement and modulation of upconversion photoluminescence by bending lanthanide doped perovskite oxides - 5587823.pdf

Supplemental Documen

A Spiro-MeOTAD/Ga₂O₃/Si p‑i‑n Junction Featuring Enhanced Self-Powered Solar-Blind Sensing via Balancing Absorption of Photons and Separation of Photogenerated Carriers

Solar blind ultraviolet (SBUV) self-powered photodetectors (PDs) have a great number of applications in civil and military exploration. Ga2O3 is a prospective candidate for SBUV detection owing to its reasonable bandgap corresponding to the SBUV waveband. Nevertheless, the previously reported Ga2O3 photovoltaic devices had low photoresponse performance and were still far from the demands of practical application. Herein, we propose an idea of using spiro-MeOTAD (spiro) as the SBUV transparent conductive layer to construct p-i-n PDs (p-spiro/Ga2O3/n-Si). With the aid of double built-in electric fields, the designed p-i-n PDs could operate without any external power source. Furtherly, the influence of spiro thickness on improving the photoelectric performance of devices is investigated in detail and the optimum device is achieved, translating to a peak responsivity of 192 mA/W upon a weak 254 nm light illumination of 2 μW/cm2 at zero bias. In addition, the I–t curve of our PD shows binary response characteristics and a four-stage current response behavior under a small forward bias, and also, its underlying working mechanism is analyzed. In sum, this newly developed device presents great potential for booming the high energy-efficient optoelectronic devices in the short run

Ultrahigh Gain Solar Blind Avalanche Photodetector Using an Amorphous Ga₂O₃‑Based Heterojunction

Solar blind photodetectors with a cutoff wavelength within the 200–280 nm region is attracting much attention due to their potential civilian and military applications. The avalanche photodetectors (APDs) formed based on wide-bandgap semiconductor Ga2O3 are expected to meet emerging technological demands. These devices, however, suffer from limitations associated with the quality of as-grown Ga2O3 or the difficulty in alleviating the defects and dislocations. Herein, high-performance APDs incorporating amorphous Ga2O3 (a-Ga2O3)/ITO heterojunction as the central element have been reliably fabricated at room temperature. The a-Ga2O3-based APDs exhibits an ultrahigh responsivity of 5.9 × 104 A/W, specific detectivity of 1.8 × 1014 Jones, and an external quantum efficiency up to 2.9 × 107% under 254 nm light irradiation at 40 V reverse bias. Notably, the gain could reach 6.8 × 104, indicating the outstanding capability for ultraweak signals detection. The comprehensive superior capabilities of the a-Ga2O3-based APDs can be ascribed to the intrinsic carrier transport manners in a-Ga2O3 as well as the modified band alignment at the heterojunctions. The trade-off between low processing temperature and superior characteristics of a-Ga2O3 promises greater design freedom for realization of wide applications of emerging semiconductor Ga2O3 with even better performance since relieving the burden on the integration progress

Over 5 × 10³‑Fold Enhancement of Responsivity in Ga₂O₃‑Based Solar Blind Photodetector via Acousto–Photoelectric Coupling

The emergence of the wide-band-gap semiconductor Ga2O3 has propelled it to the forefront of solar blind detection activity owing to its key features. Although various architectures and designs of Ga2O3-based solar blind photodetectors have been proposed, their performance still falls short of commercial standards. In this study, we demonstrate a method to enhance the performance of a simple metal–semiconductor–metal-structured Ga2O3-based solar blind photodetector by exciting acoustic surface waves. Specifically, we demonstrate that under a bias voltage of 100 mV and a radio frequency signal of 20 dBm, the responsivity and detectivity can increase from 2.78 to 1.65 × 104 A/W and from 8.35 × 1014 to 2.66 × 1016 jones, respectively, rivaling a commercial photomultiplier tube. The over 5 × 103-fold enhancement in responsivity could be attributed to the acousto–photoelectric coupling mechanism. Furthermore, since surface acoustic waves can also serve as signal receivers, such photodetectors offer the prospect of dual-mode detection. Our findings reveal a promising pathway for achieving high-performance Ga2O3-based electronics and optoelectronics