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• The piezoelectric and pyroelectric properties were discovered in the β-Ga2O3 crystal due to a seldom reported contribution of crystal structure with non-centrosymmetrical C2 space group. • Compared to traditional Ga 2 O 3 -based PD, the as-used PD demonstrated a self-powered property and a broadband response beyond the bandgap limitations, ranging from 200 nm (DUV) to 980 nm (infrared). • The Ag/β-Ga 2 O 3 PD revealed an enhanced opto-electronic performance at both high and low temperatures, and a good long-term stability, indicating great advantages for applications in harsh environments. β-Ga 2 O 3 , as one of the important 4th generation semiconductors, is widely used in solar-blind ultraviolet (UV) detectors with a short detection range of 200–280 nm benefiting from its ultra-wide bandgap, strong radiation resistance, and excellent chemical and thermal stabilities. Here, a self-powered photodetector (PD) based on an Ag/β-Ga 2 O 3 Schottky heterojunction was designed and fabricated. Through a subtle design of electrodes, the pyro-phototronic effect was discovered, which can be coupled to the common photovoltaic effect and further enhance the performance of the PD. Compared to traditional Ga 2 O 3 -based PD, the as-used PD exhibited a self-driving property and a broadband response beyond the bandgap limitations, ranging from 200 nm (deep UV) to 980 nm (infrared). Moreover, the photoresponse time was greatly shrunk owing to the coupling effect. Under laser irradiation, with a wavelength of 450 nm and a power density of 8 mW cm‒2, the photocurrent could be improved by around 41 times compared with the sole photovoltaic effect. Besides, the performances of the Schottky PD were enhanced at both high and low temperatures. The device also possessed long-term working stability. This paper not only reveals basic physics lying in the 4th generation semiconductor Ga 2 O 3 but also sheds light on the multi-encryption transmission of light information using this PD. Based on the pyro-phototronic and photovoltaic effects, a self-powered Ag/β-Ga 2 O 3 PD was designed and fabricated with a broadband response ranging from 200 to 980 nm. The as-fabricated PD also revealed an enhanced opto-electronic performance at both high and low temperatures and long-term working stability. [Display omitted] [ABSTRACT FROM AUTHOR]

Additive manufacturing (AM) has attracted significant attention in recent years based on its wide range of applications and growing demand. AM offers the advantages of production flexibility and design freedom. In this study, we considered a practical variant of the batch-processing-machine (BPM) scheduling problem that arises in AM industries, where an AM machine can process multiple parts simultaneously, as long as the two-dimensional rectangular packing constraint is not violated. Based on the set-partitioning formulation of our mixed-integer programming (MIP) model, a branch-and-price (B&P) algorithm was developed by embedding a column-generation technique into a branch-and-bound framework. Additionally, a novel labelling algorithm was developed to accelerate the column-generation process. Ours is the first study to provide a B&P algorithm to solve the BPM scheduling problem in the AM industry. We tested the performance of our algorithm using a modern MIP solver (Gurobi) and real data from a 3D printing factory. The results demonstrate that for most instances tested, our algorithm produces results similar or identical to those of Gurobi with reasonable computation time and outperforms Gurobi in terms of solution quality and running time on some large instances.

Tribovoltaic nanogenerators (TVNGs) usually consist of two heterogeneous materials with disparate Fermi levels. However, TVNGs based on two same semiconductors with uniformed Fermi levels have been rarely reported, as they are believed to lack the sufficient potential difference necessary to drive tribo-induced carriers’ separation and collection, resulting in minimal or negligible electricity production. Here, tribovoltaic nanogenerators based on two homojunction semiconductors (H-TVNGs) with the same doping concentration are proposed and designed. The H-TVNGs were demonstrated to be driven by abundant surface states introduced through laser cutting at the slider boundaries and surfaces, which further lead to the bending of interface energy bands. Upon two sliders of different sizes (with different degrees of band bending) come into contact, the built-in electric field at the interface will be established and drive tribo-induced carriers, leading to the production of a direct-current (DC) electrical signal. The performance of H-TVNGs could be effectively amplified or regulated by many factors, including laser cutting power, semiconductor surface roughness, slider shape, and the interface media, etc. These compelling findings reveal innovative physics in tribovoltaic effect, offer special insights for designing high-performance TVNGs, and provide effective strategies for device output optimization.

Rechargeable zinc-air batteries are attracting great attention due to their high theoretical specific energy, safety, and economic viability. However, their performance and large-scale practical applications are largely limited by poor durability and high overpotential on the air-cathode due to the slow kinetics of the oxygen evolution and reduction reactions (OER/ORR). Therefore, it is highly desired to develop new bifunctional catalysts to improve the OER and ORR kinetics. In this paper, NiCo2Se4 nanowires were uniformly grown on carbon fiber paper (CFP) for the first time. With an overpotential for OER of 327 mV, NiCo2Se4 nanowires show a better performance than RuO2 (350 mV) and a high stability. Moreover, their half-wave potential of 0.77 V and limiting current density of 3.75 mA*cm[?]2 make it a promising non-precious-metal catalyst for ORR, with performance close to Pt/C (0.87 V, 3.7 mA*cm[?]2). The excellent performance is attributed to the nanowire morphology with efficient 1D electronic pathways, high conductivity of NiCo2Se4 and an enhanced electronic structure, thanks to a mixed valence of nickel and cobalt ions.

Rechargeable zinc–air batteries are attracting great attention due to their high theoretical specific energy, safety, and economic viability. However, their performance and large-scale practical applications are largely limited by poor durability and high overpotential on the air-cathode due to the slow kinetics of the oxygen evolution and reduction reactions (OER/ORR). Therefore, it is highly desired to develop new bifunctional catalysts to improve the OER and ORR kinetics. In this paper, NiCo2Se4nanowires were uniformly grown on carbon fiber paper (CFP) for the first time. With an overpotential for OER of 327 mV, NiCo2Se4nanowires show a better performance than RuO2(350 mV) and a high stability. Moreover, their half-wave potential of 0.77 V and limiting current density of 3.75 mA·cm−2make it a promising non-precious-metal catalyst for ORR, with performance close to Pt/C (0.87 V, 3.7 mA·cm−2). The excellent performance is attributed to the nanowire morphology with efficient 1D electronic pathways, high conductivity of NiCo2Se4and an enhanced electronic structure, thanks to a mixed valence of nickel and cobalt ions.