Room-temperature MoTe2/InSb heterostructure large-area terahertz detector

As a building block for terahertz system, terahertz detector is expected to achieve high-performance, roomtemperature, low-cost and large-area detection available. However, the state-of-the-art technologies still suffer from various drawbacks. This paper presents a MoTe2/InSb heterostructure large-area terahertz detector. With the photoactive region of heterostructure, carriers are allowed to assemble within the interface due to the carrier mobility difference, resulting in detection sensitivity improvement. The structures and bonding of MoTe2/InSb heterostructure were characterized by Raman spectroscopy. Besides, large-scale interdigital electrodes with subwavelength spacing are employed at the bottom of photoactive region, which contrasts with normal electrodes coated on both sides of the active layer, endowing a large effective detection area of 2 mm x 6.65 mm with the detector. Subwavelength electrodes spacing not only facilitates the directional migration of carriers, but also induces electromagnetic induced well (EIW) effects to obtain extraordinary performance. As a result, the detector achieves a noise equivalent power (NEP) of 2.66 pW Hz-1/2 and a detectivity (D*) of 0.53 x 1012 cm Hz1/ 2 W-1 under 0.1 THz radiation at room temperature. The proposed high-performance terahertz detector exhibits remarkable prospects in varieties of applications.