High-quality reconfigurable MoTe2 p–i–n n–i–p n–i–n p–i–p homojunctions are realized successfully presenting rectification behaviors with ideality factors approaching 10 and ultralow dark currents les

The successful fabrication of high-quality reconfigurable MoTe2 homojunctions (p-i-n, n-i-p, n-i-n, p-i-p) has been achieved, exhibiting rectification behaviors with ideality factors approaching 1.0 and ultralow dark currents less than 90 pA. The use of waveguide-assisted MoTe2 absorption enables sensitive photodetection in the telecommunication O-band ranging from 1260 to 1340 nm, which is in close proximity to MoTe2's absorption band-edge. A competitive photoresponsivity of 0.4 A/W has been achieved with a light on/off current ratio exceeding 104 and a record-high normalized photocurrent-to-dark-current ratio of 106 mW-1. The combination of the ultrasmall capacitance of the p-i-n homojunction and high carrier mobility of MoTe2 promises a high dynamic response bandwidth close to 34.0 GHz