The zero‐magnetic‐field nonlinear Hall effect (NLHE) refers to the second‐order transverse current induced by an applied alternating electric field; it indicates the topological properties of inversion‐symmetry‐breaking crystals. Despite several studies on the NLHE induced by the Berry‐curvature dipole in Weyl semimetals, the direct current conversion by rectification is limited to very low driving frequencies and cryogenic temperatures. The nonlinear photoresponse generated by the NLHE at room temperature can be useful for numerous applications in communication, sensing, and photodetection across a high bandwidth. In this study, observations of the second‐order NLHE in type‐II Dirac semimetal CoTe2 under time‐reversal symmetry are reported. This is determined by the disorder‐induced extrinsic contribution on the broken‐inversion‐symmetry surface and room‐temperature terahertz rectification without the need for semiconductor junctions or bias voltage. It is shown that remarkable photoresponsivity over 0.1 A W−1, a response time of approximately 710 ns, and a mean noise equivalent power of 1 pW Hz−1/2 can be achieved at room temperature. The results open a new pathway for low‐energy photon harvesting via nonlinear rectification induced by the NLHE in strongly spin–orbit‐coupled and inversion‐symmetry‐breaking systems, promising a considerable impact in the field of infrared/terahertz photonics.

As the heart and with the tremendous applications of terahertz technology, photodetectors suffer from considerable drawbacks imposed by weak optical absorption, and inefficient charge-separation mechanisms. In article number 2209557, Antonio Politano, Lin Wang, and co-workers report the nonlinear Hall effect operating at terahertz frequencies within strong spin-polarized topological states in CoTe 2 without invoking any semiconductor junctions or bias voltage, opening up fascinating route toward quantum wavefunction engineering.

Inorganic perovskites have become a widely investigated candidate for fabrication of high-performance micro-devices due to their excellent optoelectronic properties and stability to the environment. Especially, their excellent lasing characteristics as a micro/nanolaser source, combined with flexible substrates, have great potential in the field of wearable or foldable photonic device applications. Here, the high-quality CsPbBr 3 perovskite microsheets with stress-induced grooves are directly prepared on the ultrathin fluorine mica by the chemical vapor deposition method, and the single-mode lasers are realized in these large-size (>15 × 15 µm) microsheets. Thanks to the flexibility of mica, bending induced tensile strain on CsPbBr 3 microsheet causes the laser mode blueshift continuously and reversibly with 15.3 meV % −1 , this can be well explained by the Lorentz oscillator model under lasing conditions. Furthermore, by using the first-principles calculation, it is clarified that the bandedge blueshift originates from the distortion of {PbBr 6 } 4− octahedra and the consequential increase of the bond length of Pb-Br 3 and the Pb-Br 3 -Pb bond angle. This work opens up a new way to realize on-chip single-mode lasers with microstructures, and is helpful for the application of flexible photonic device in the fields of integrated on-chip sensors.