Entropy engineering has emerged as a promising paradigm for tailoring the electronic and photoelectric properties of materials. Although high-entropy transition metal sulfides have been achieved, entropy engineering in two-dimensional (2D) tellurides remains challenging. In this work, we report the successful synthesis of a 1T' monolayer heptanary medium-entropy (ME) alloy (Mo_aW_bFe_cCo_dS_xSe_yTe_z) via a one-step chemical vapor deposition method. Advanced characterizations, including scanning transmission electron microscopy, energy dispersive X-ray spectroscopy, and electron energy loss spectroscopy confirm the uniform atomic-level distribution of the seven constituent elements within the alloy. The 1T' ME alloy device exhibits a high drain current of ~ 6.5 mA, which is 216 times higher than the ~ 30 μA observed in pristine 1T' MoTe₂. Furthermore, the 1T' ME alloy photodetector exhibits responsivities of 27.92 A/W at 1064 nm and 63.74 A/W at 1550 nm, outperforming those of the pristine 1T' MoTe₂ by more than two orders of magnitude. This remarkable enhancement is attributed to the reduced Schottky barrier (15.9 meV) at the 1T' ME alloy/electrode interface, along with the enhanced conductance (0.43 S) and reduced thermal activation energy (4.1 meV) in the 1T' ME alloy, collectively facilitating more efficient carrier injection and transport. Our work provides a distinct pathway for tailoring the properties of transition metal dichalcogenides through entropy engineering and offers valuable insights for the design of high-performance infrared photodetectors.

Intrinsic ferroelectric materials play a critical role in the development of high-density integrated device. Despite some two-dimensional (2D) ferroelectrics have been reported, the research on one-dimensional (1D) intrinsic ferroelectric materials remains relatively scare since 1D atomic structures limit their van der Waals (vdW) epitaxy growth. Here, we report the synthesis of 1D intrinsic vdW ferroelectric SbSI nanowires via a confined-space chemical vapor deposition. By precisely controlling the partial vapor pressure of I₂ and reaction temperature, we can effectively manipulate kinetics and thermodynamics processes, and thus obtain high quality of SbSI nanowires, which is determined by Raman spectroscopy and high-resolution scanning transmission electron microscopy characterizations. The ferroelectricity in SbSI is confirmed by piezo-response force microscopy measurements and the ferroelectric transition temperature of 300 K is demonstrated by second harmonic generation. Moreover, the in-plane polarization switching can be maintained in the thin SbSI nanowires with a thickness of 20 nm. Our prepared 1D vdW ferroelectric SbSI nanowires not only enrich the vdW ferroelectric systems, but also open a new possibility for high-power energy storage nanodevices.