Broadband Room‐Temperature Photodetection via InBiTe₃ Nanosheet

Abstract

Broadband room‐temperature photodetection has become a pressing need as application requirements for communication, imaging, spectroscopy, and sensing have evolved. Topological insulators (TIs) have narrow bandgap structures with a wide absorption spectral response range, which should meet the requirements of broadband detection. However, owing to their high carrier concentration and low carrier mobility resulting in poor noise equivalent power (NEP), they are generally considered unsuitable for photodetection. Here, InBiTe3 alloy nanosheet formed by doping In2Te3 into Bi2Te3(≈ 1:1) is utilized, effectively improving carrier mobility by over ten times while maintaining a narrow bandgap structure, to fabricate a broadband photodetector covering a wide response range from visible to millimeter wave (MMW). Under the synergistic multi‐mechanism of the photoelectric effect in the visible−infrared region and the electromagnetic‐induced potential well (EIW) effect in Terahertz band, the performance of NEP = 75 pW Hz−1/2 and response time τ ≈100 µs in visible to infrared band and the performance of NEP = 6.7 × 10−3 pW Hz−1/2, τ ≈8 µs in Terahertz region are achieved. The results demonstrate the promising prospects of topological insulator alloy (like InBiTe3) nanosheet in optoelectronic detection applications and provide a direction for the research into high‐performance broadband photoelectric detectors via TIs.

Strong Covalent Coupling in Vertically Layered SnSe2/PTAA Heterojunctions Enabled High Performance Inorganic–Organic Hybrid Photodetectors

“…Owing to their outstanding electrical and optical properties, including high carrier mobility, suitable band gap, and strong light–matter interactions, the newly explored two-dimensional (2D) materials show unique applications in cutting-edge devices, such as sensors, optical imaging, field-effect transistors (FET), and photodetectors (PDs). − The group-IV metal dichalcogenides, particularly earth-abundant SnSe 2 with its intrinsic n-type characteristics, display a high electron mobility of 462.6 cm 2 V –1 s –1 and a layer-dependent bandgap. , The bandgap of multilayer and bulk SnSe 2 is 1.73 and 1.2 eV, respectively, suggesting that it could be an ideal material choice for UV–visible broadband PDs. , For example, Lu et al achieved broadband (450–1064 nm) PDs based on SnSe 2 thin films, with a responsivity of 21.4 μA/W and a detectivity of 6.1 × 10 5 Jones at 450 nm . However, the morphology of SnSe 2 nanosheets fabricated by established CVD or mechanical exfoliation methods is typically discretized or randomized, which hinders its practical applications.…”