High‐entropy (HE) MXenes represent a novel class of 2D materials within the MXene family, which are drawing widespread attention because of their diverse compositions and robust physicochemical properties. However, the exploration of HE‐MXenes in optoelectronic domains is relatively limited. This study unveils the rapid photoresponse and superior nonlinear optical (NLO) characteristics of HE‐MXene TiVCrMoC3Tx nanosheets (NSs) through comparison with ordinary MXene Ti3C2Tx NSs. Transient absorption spectroscopy reveals that the few‐layer TiVCrMoC3Tx NSs excel in photoelectrochemical‐type photodetectors with swift response properties. Additionally, the advantage of HE structures is further validated by NLO measurement system, which show that few‐layer TiVCrMoC3Tx NSs exhibit stronger saturable absorption than Ti3C2Tx NSs. First‐principles calculations based on the special quasi‐random structure method reveal that the transition behavior of HE‐MXene is similar to that of a semiconductor with direct bandgap, and this is ascribed to the main reason of strong photoelectric response. Taking advantage of the NLO properties of the TiVCrMoC3Tx NSs, all‐optical devices based on these NSs are applied to mode‐locked fiber lasers at 1, 1.5, and 2 µm wavebands, respectively. This investigation provides meaningful guidance for the future design and application of HE‐MXenes in high‐performance optoelectronic devices.

中文翻译：

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高熵 MXene 在高效光电化学型光电探测器和宽带锁模器中的新兴应用

高熵 (HE) MXene 代表了 MXene 家族中一类新型的 2D 材料，由于其多样化的成分和强大的物理化学性质而受到广泛关注。然而，HE-MXenes在光电领域的探索相对有限。这项研究揭示了 HE-MXene TiVCrMoC 的快速光响应和卓越的非线性光学 (NLO) 特性3时间X纳米片（NSs）与普通 MXene Ti 的比较3C2时间XNS。瞬态吸收光谱表明，少层 TiVCrMoC3时间XNS 在具有快速响应特性的光电化学型光电探测器方面表现出色。此外，NLO测量系统进一步验证了HE结构的优势，表明少层TiVCrMoC3时间XNSs 表现出比 Ti 更强的饱和吸收3C2时间XNS。基于特殊准随机结构方法的第一性原理计算表明，HE-MXene的跃迁行为与直接带隙半导体相似，这是其强光电响应的主要原因。利用 TiVCrMoC 的 NLO 特性3时间XNS，基于这些NS的全光学器件分别应用于1、1.5和2 µm波段的锁模光纤激光器。这项研究为HE-MXenes在高性能光电器件中的未来设计和应用提供了有意义的指导。