Zeng Longhui, Wu Di, Jie Jiansheng, Ren Xiaoyan, Hu Xin, Lau Shu Ping, Chai Yang, Tsang Yuen Hong
Department of Applied Physics, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, P. R. China.
School of Physics and Microelectronics, Key Laboratory of Material Physics Ministry of Education, Zhengzhou University, Zhengzhou, Henan, 450052, P. R. China.
Adv Mater. 2020 Dec;32(52):e2004412. doi: 10.1002/adma.202004412. Epub 2020 Nov 9.
Mid-infrared (MIR) photodetection, covering diverse molecular vibrational regions and atmospheric transmission windows, is vital to civil and military purposes. Versatile use of MIR photodetectors is commonly dominated by HgCdTe alloys, InSb, and quantum superlattices, which are limited by strict operation demands, high-cost, and environmental toxicity. Despite the rapid advances of black phosphorus (BP)-based MIR photodetectors, these are subject to poor stability and large-area integration difficulty. Here, the van der Waals (vdW) epitaxial growth of a wafer-scale 2D platinum ditelluride (PtTe ) layer is reported via a simple tellurium-vapor transformation approach. The 2D PtTe layer possesses a unique mosaic-like crystal structure consisting of single-crystal domains with highly preferential [001] orientation along the normal direction, reducing the influence of interface defects and ensuring efficient out-of-plane carrier transportation. This characteristic, combined with the wide absorption of PtTe and well-designed vertical device architecture, makes the PtTe /Si Schottky junction photodetector capable of sensing ultra-broadband light of up to 10.6 µm with a high specific detectivity. Also, the photodetector exhibits an excellent room-temperature infrared-imaging capability. This approach provides a new design concept for high-performance, room-temperature MIR photodetection based on 2D layered materials.
中红外（MIR）光电探测覆盖了不同的分子振动区域和大气传输窗口，对民用和军事用途都至关重要。MIR光电探测器的广泛应用通常由汞镉碲合金、锑化铟和量子超晶格主导，这些材料受到严格的操作要求、高成本和环境毒性的限制。尽管基于黑磷（BP）的MIR光电探测器取得了快速进展，但它们存在稳定性差和大面积集成困难的问题。在此，通过一种简单的碲气转化方法报道了晶圆级二维二碲化铂（PtTe₂）层的范德华（vdW）外延生长。二维PtTe₂层具有独特的马赛克状晶体结构，由沿法线方向具有高度优先[001]取向的单晶域组成，减少了界面缺陷的影响并确保了有效的面外载流子传输。这一特性，结合PtTe₂的宽吸收和精心设计的垂直器件结构，使得PtTe₂/Si肖特基结光电探测器能够以高比探测率感测高达10.6μm的超宽带光。此外，该光电探测器还具有出色的室温红外成像能力。这种方法为基于二维层状材料的高性能室温MIR光电探测提供了一种新的设计理念。
