LAUSR

Mixed-dimensional vdW heterostructures based on two-dimensional (2D) materials exhibit immense potential in infrared optoelectronic applications. But, the weak vdW coupling results in limiting performance of infrared optoelectronic device. Here, we exploit a gapless heterostructure that S dangling bonds of non-layered PbS are connected to the bonding sites of MoS2 (with factitious S vacancies) via strong orbital hybridization. The strong interface coupling leads to ultrahigh responsivity and photogain (G) exceeding 105, and the detectivity (D*) is greater than 1014 Jones. More importantly, the gapless heterostructure shows fast rise and decay times about 47 μs and 49 μs, respectively, which is five orders of magnitude faster than that of transferred vdW heterostructures. Furthermore, an ultrahigh photon-triggered on/off ratio of 1.6×106 is achieved, which is four orders of magnitude higher than that of transferred vdW heterostructures. This architecture can offer an effective approach for advanced infrared optoelectronic devices.