Semiconductor-based surface enhanced Raman spectroscopy (SERS) platforms take advantage of the multifaceted tunability of semiconductor materials to realize specialized sensing demands in a wide range of applications. However, until quite recently, semiconductor-based SERS materials have generally exhibited low activity compared to conventional noble metal substrates, with enhancement factors (EF) typically reaching 10³, confining the study of semiconductor-based SERS to purely academic settings. In recent years, defect engineering has been proposed to effectively improve the SERS activity of semiconductor materials. Defective semiconductors can now achieve noble-metal-comparable SERS enhancement and exceedingly low, nano-molar detection concentrations towards certain molecules. The reason for such success is that defect engineering effectively harnesses the complex enhancement mechanisms behind the SERS phenomenon by purposefully tailoring many physicochemical parameters of semiconductors. In this perspective, we introduce the main defect engineering approaches used in SERS-activation, and discuss in depth the electromagnetic and chemical enhancement mechanisms (EM and CM, respectively) that are influenced by these defect engineering methods. We also introduce the applications that have been reported for defective semiconductor-based SERS platforms. With this perspective we aim to meet the imperative demand for a summary on the recent developments of SERS material design based on defect engineering of semiconductors, and highlight the attractive research and application prospects for semiconductor-based SERS.

Novel MOF-derived 3D vertically stacked Mn₂O₃@C/CNTFs for fiber-shaped zinc-ion batteries with excellent electrochemical performance and weavability.

With the increasing interest in the application of electrochromism to flexible and wearable electronics in recent years, flexible electrochromic devices (ECDs) that can function at extreme temperatures are required. However, the functionalities of flexible ECDs are severely hampered by the inadequate choice of electrolytes, which might ultimately result in performance fading during low‐ and high‐temperature operations. Here, we develop a deep eutectic solvent (DES)‐based gel electrolyte that can maintain its optical, electrical, and mechanical properties over a wide range of temperatures (−40 to 150°C), exhibiting an extremely high visible‐range transmittance over 90%, ion conductivity of 0.63 mS cm⁻¹, and fracture strain exceeding 2000%. Owing to the excellent processability of the DES‐based electrolytes, provided by dynamic interactions such as the lithium and hydrogen bonding between the DES and polymer matrix, a directly written patterning in ECDs is realized for the first time. The fabricated ECDs exhibit an excellent electrochromic behavior superior to the behavior of the ECDs fabricated with traditional gel electrolytes. The introduction of such DES‐based electrolytes is expected to pave the way for a widespread application of electrochromic products. image