Ultrabroadband Photodetectors up to 10.6 µm Based on 2D Fe₃O₄ Nanosheets

Abstract

The ultrabroadband spectrum detection from ultraviolet (UV) to long‐wavelength infrared (LWIR) is promising for diversified optoelectronic applications of imaging, sensing, and communication. However, the current LWIR‐detecting devices suffer from low photoresponsivity, high cost, and cryogenic environment. Herein, a high‐performance ultrabroadband photodetector is demonstrated with detecting range from UV to LWIR based on air‐stable nonlayered ultrathin Fe3O4 nanosheets synthesized via a space‐confined chemical vapor deposition (CVD) method. Ultrahigh photoresponsivity (R) of 561.2 A W−1, external quantum efficiency (EQE) of 6.6 × 103%, and detectivity (D*) of 7.42 × 108 Jones are achieved at the wavelength of 10.6 µm. The multimechanism synergistic effect of photoconductive effect and bolometric effect demonstrates the high sensitivity for light with any light intensities. The outstanding device performance and complementary mixing photoresponse mechanisms open up new potential applications of nonlayered 2D materials for future infrared optoelectronic devices.

Van der Waals Epitaxial Growth of Mosaic‐Like 2D Platinum Ditelluride Layers for Room‐Temperature Mid‐Infrared Photodetection up to 10.6 µm

“…Significantly, the detection range of the PtTe 2 /Si photodetector is among the broadest in these photodetectors. Also, the response speed and specific detectivity are superior to most of 2D TMD‐based or 2D–3D vdW heterostructure photodetectors, [ 46–57 ] and close to some commercial low‐temperature MIR photodiodes made of InAs/GaSb, InSb, InAsSb, and HgCdTe. [ 1,2,9 ] The outstanding performance of the PtTe 2 /Si vertical Schottky junction photodetector can be attributed to the following factors: i) The 2D PtTe 2 layer possesses a strong light absorption spanning an ultra‐wide spectrum range, enabling the ultra‐broadband photodetection of the PtTe 2 /Si photodetector up to 10.6 µm.…”

Carbon-incorporated Fe3O4 nanoflakes: high-performance faradaic materials for hybrid capacitive deionization and supercapacitors

“…The designed nanostructures, especially two-dimensional (2D) nanosheets/ nanoflakes, usually exhibit unusual characteristics beyond ordinary structures, including increased accessible surface area, shortened ion diffusion pathway, and more exposed electrochemically active sites. 15,16 However, the construction of the 2D Fe 3 O 4 architecture is only realized in some studies with complex synthesis steps and high production costs, 17 and it is still in its infancy and extremely challenging.…”

Electronic Modulation of Non‐van der Waals 2D Electrocatalysts for Efficient Energy Conversion

“…Non‐vdW 2D materials include metals and metal chalcogenides, oxides, nitrides, and phosphides. The methods used to synthesize non‐vdW 2D materials are summarized in Table 1 and can be divided into three categories: confined synthesis (e.g., self‐assembly, [ 25–33 ] oriented attachment, [ 34–40 ] vdW exfoliation, [ 41–45 ] and self‐limited CVD, [ 46–55 ] ), topochemical synthesis (e.g., lamellar intermediate‐assisted exfoliation, [ 56–64 ] topochemical transformation, [ 65–75 ] and template‐assisted growth, [ 76–84 ] ), and other emerging strategies (e.g., repeating folding and calendaring, [ 85 ] electrophoretic synthesis, [ 86 ] 2D‐to‐3D transformation, [ 87 ] and so on. [ 88–90 ] ).…”