No abstract

Abstract2D transition metal dichalcogenides have shown great potential for next‐generation microelectronic devices owing to their ability to prolong the life of Moore's law by mitigating the short‐channel effect. Recently, many efforts have been made on doping 2D films to create p‐n junctions, in which plasma implantation has been placed great expectations due to its CMOS process compatibility. However, ultrathin vertical 2D p‐n homostructure with excellent rectification behaviors have rarely been studied so far. Herein, MoS2 van der Waals p‐n homojunctions are fabricated by highly efficient N2 plasma implantation. Kelvin probe force microscope reveals the surface potential difference of ≈130 mV between n‐MoS2 and p‐MoS2. The fabricated field‐effect transistor (FET) presents a high rectification ratio up to 3.1 × 10–3 at the gate bias VGS = 20 V, which is over 20 times larger than that of the vertical homojunction obtained by surface chemical doping. The forward current is mainly dominated by both the interlayer recombination and band‐to‐band tunneling, while the ultra‐low reverse current in the order of 10 pA is governed by direct tunneling. The results demonstrate a new CMOS‐compatible way to fabricate vertical 2D homojunction, which is the basic structure of many low‐dimensional microelectronic devices.

Perovskite materials have been widely used to fabricate solar cells, laser diodes and other photodevices, owing to the advantage of high absorption coefficient, long carrier life and shallow defect energy levels. However, due to easy hydrolysis, it is difficult to fabricate perovskite micro-nano devices. Herein, we developed a water-free device fabrication technology and fabricated a two-dimensional (C6H5C2H4NH3)2PbI4 ((PEA)2PbI4) two-color blue-green light detector, which exhibits high detection performance under the illumination of two-color lasers (λ= 460 nm, 532 nm). Compared with bulk devices, the dark current of the fabricated devices (10−11 A) was reduced by 2 orders of magnitude. The peak responsivity and detectivity are about 1 A/W and 1011 Jones, respectively. The photodetection performance of the device is basically the same under the two-color lasers. Our results provide a new process to fabricate perovskite microelectronic devices, and the fabricated photodetector shows great application prospects in underwater detection, owing to the blue-green window existing in water.