Stable, highly-responsive and broadband photodetection based on large-area multilayered WS₂ films grown by pulsed-laser deposition.

Although two-dimensional (2D) materials have attracted considerable research interest for use in the development of innovative wearable optoelectronic systems, the integrated optoelectronic performance of 2D materials photodetectors, including flexibility, transparency, broadband response and stability in air, remains quite low to date. Here, we demonstrate a flexible, transparent, high-stability and ultra-broadband photodetector made using large-area and highly-crystalline WSe ₂ films that were prepared by pulsed-laser deposition (PLD). Benefiting from the 2D physics of WSe ₂ films, this device exhibits excellent average transparency of 72% in the visible range and superior photoresponse characteristics, including an ultra-broadband detection spectral range from 370 to 1064 nm, reversible photoresponsivity approaching 0.92 A W ⁻¹ , external quantum efficiency of up to 180% and a relatively fast response time of 0.9 s. The fabricated photodetector also demonstrates outstanding mechanical flexibility and durability in air. Also, because of the wide compatibility of the PLD-grown WSe ₂ film, we can fabricate various photodetectors on multiple flexible or rigid substrates, and all these devices will exhibit distinctive switching behavior and superior responsivity. These indicate a possible new strategy for the design and integration of flexible, transparent and broadband photodetectors based on large-area WSe ₂ films, with great potential for practical applications in the wearable optoelectronic devices.

Here, we report a vertically-constructed ultra-broadband photodetector based on a TI Bi ₂ Te ₃ –Si heterostructure.

2D materials and their hybrid structures have high application prospects in broadband photodetection, making them promising complements to traditional schemes.