Being capable of sensing broadband infrared (IR) light is vitally important for wide-ranging applications from fundamental science to industrial purposes. Two-dimensional (2D) topological semimetals are being extensively explored for broadband IR detection due to their gapless electronic structure and the linear energy dispersion relation. However, the low charge separation efficiency, high noise level, and on-chip integration difficulty of these semimetals significantly hinder their further technological applications. Here, we demonstrate a facile thermal-assisted tellurization route for the van der Waals (vdW) growth of wafer-scale phase-controlled 2D MoTe₂ layers. Importantly, the type-II Weyl semimetal 1T′-MoTe₂ features a unique orthorhombic lattice structure with a broken inversion symmetry, which ensures efficient carrier transportation and thus reduces the carrier recombination. This characteristic is a key merit for the well-designed 1T′-MoTe₂/Si vertical Schottky junction photodetector to achieve excellent performance with an ultrabroadband detection range of up to 10.6 µm and a large room temperature specific detectivity of over 10⁸ Jones in the mid-infrared (MIR) range. Moreover, the large-area synthesis of 2D MoTe₂ layers enables the demonstration of high-resolution uncooled MIR imaging capability by using an integrated device array. This work provides a new approach to assembling uncooled IR photodetectors based on 2D materials.

Self-powered solar-blind photodetectors based on diamond/β-Ga ₂ O ₃ heterojunctions have been fabricated and high quality solar-blind images have been realized.

Fluorescent carbon dots (CDs) with a size smaller than 10 nm, excellent biocompatibility, and low to no cytotoxicity are considered as a rising star in nanomedicine. In this report, for the first time we demonstrate that green-emitting CDs with a carboxyl-rich surface can be employed as a trackable drug delivery agent for localized cancer treatment in a mouse model. The CDs are conjugated with the cancer drug, Doxorubicin (DOX), via non-covalent bonding, utilizing the native carboxyl groups on CDs and the amine moiety on DOX molecules. The pH difference between cancer and normal cells was successfully exploited as the triggering mechanism for DOX release. Our in vivo study demonstrated that the fluorescent CDs can serve as a targeted drug delivery system for localized therapy, and the stimuli-responsive non-covalent bonding between the nanodot carrier and the drug molecule is sufficiently stable in complex biological systems. Taken together, our work provides a strategy to promote the potential clinical application of CDs in cancer theranostics.