SiAs with excellent properties has been widely reported in recent years. However, the stubborn p-type conductivity of SiAs itself poses a significant challenge in achieving n-type conductivity. Furthermore, for the two-dimensional (2D) SiAs photodetector, it is also essential to improve its photoelectric performance. SiAs, as one of the representative layered semiconductors of the IV–V group, is considered to be an exemplary alternative catalyst for the HER. Substitution doping has been proven effective in adjusting its intrinsic properties and improving the device performance. Here, replacing doping is considered an effective method to adjust its intrinsic properties, improve the optoelectronic performance of devices, and enhance the HER performance of catalysts. This article demonstrates the preparation of SiAs and SiAs single crystals with different Sc doping concentrations using the chemical vapor transport (CVT) method. A series of optical characterization techniques are applied to prove that Sc is successfully doped into the SiAs lattice by replacing Si. The effect of Sc doping on the electrocatalytic properties of SiAs in the HER is systematically studied through experimental studies and density functional theory (DFT) calculations. We find that doping the rare earth element Sc into SiAs can adjust its electronic structure and reduce its adsorption-free energy for hydrogen. Compared with undoped SiAs, Sc-doped SiAs has a lower overpotential, Tafel slope, and charge transfer resistance and a larger electrochemically active surface area and turnover frequency, thus exhibiting superior catalytic activity and stability. In particular, when the Sc doping concentration reaches 0.97 at%, SiAs exhibits a low overpotential of 66 mV, a Tafel slope of 99.4 mV, and good durability at a current density of 10 mA cm⁻². In addition, field-effect transistors (FETs) and photodetectors based on 2D SiAs and Sc-SiAs were prepared, and their electrical and optoelectronic properties were investigated. Interestingly, as the Sc doping concentration increases, the FET undergoes regular changes from p-type to bipolar and finally to n-type, and its photoresponse characteristics also significantly improve. This work provides valuable guidance for designing doped IV–V group layered semiconductors and provides the HER with a new and effective catalyst to improve catalytic performance.

中文翻译：

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Sc掺杂对二维SiAs单晶电催化和光电性能的影响

近年来，具有优异性能的SiAs被广泛报道。然而，SiAs本身顽固的p型导电性对实现n型导电性提出了重大挑战。此外，对于二维（2D）SiAs光电探测器，提高其光电性能也至关重要。 SiAs作为IV-V族的代表性层状半导体之一，被认为是HER的示例性替代催化剂。替代掺杂已被证明可以有效调整其固有特性并提高器件性能。这里，替代掺杂被认为是调整其固有性质、提高器件光电性能、增强催化剂析氢性能的有效方法。本文演示了使用化学气相传输（CVT）方法制备不同 Sc 掺杂浓度的 SiAs 和 SiAs 单晶。应用一系列光学表征技术证明Sc通过取代Si成功掺杂到SiAs晶格中。通过实验研究和密度泛函理论（DFT）计算，系统地研究了Sc掺杂对SiAs在HER中电催化性能的影响。我们发现，在SiAs中掺杂稀土元素Sc可以调整其电子结构，降低其对氢的吸附自由能。与未掺杂的SiAs相比，Sc掺杂的SiAs具有较低的过电势、塔菲尔斜率和电荷转移电阻以及较大的电化学活性表面积和周转频率，从而表现出优异的催化活性和稳定性。特别地，当Sc掺杂浓度达到0.97at%时，SiAs表现出66mV的低过电势、99.4mV的塔菲尔斜率以及在10mA cm ^-2的电流密度下良好的耐久性。此外，还制备了基于2D SiAs和Sc-SiAs的场效应晶体管（FET）和光电探测器，并研究了它们的电学和光电性能。有趣的是，随着Sc掺杂浓度的增加，FET经历了从p型到双极型，最后到n型的规律变化，其光响应特性也显着改善。这项工作为设计掺杂 IV-V 族层状半导体提供了宝贵的指导，并为 HER 提供了一种新型有效的催化剂来提高催化性能。