Dual-photoconductivity in monolayer PtSe_(2) ribbons  

作　　者：Zechen Li Honglin Wang Huaipeng Wang Jing Li Fangzhu Qing Xuesong Li Dan Xie Hongwei Zhu 

机构地区：[1]State Key Lab of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing, 100084, China [2]School of Integrated Circuits, Beijing National Research Center for Information Science and Technology, Tsinghua University, Beijing, 100084, China [3]State Key Lab of Solid Waste Reuse for Building Materials, Beijing Building Materials Academy of Science Research, Beijing, 100041, China [4]Shenzhen Institute for Advanced Study, University of Electronic Science and Technology of China, Shenzhen, 518110, China

出　　处：《Nano Research》2024年第11期10189-10195,共7页纳米研究（英文版）

基　　金：supported by the National Natural Science Foundation of China(No.52172046).

摘　　要：Two-dimensional platinum diselenide (PtSe_(2)) has been explored for applications in visible and infrared photodetectors, owing to its tunable electrical and optoelectronic properties governed by layer-dependent bandgaps. Studies have explored both positive photoconductivity (PPC) and negative photoconductivity (NPC) behaviors in few-layer PtSe_(2) thin films, proposing mechanisms related to gas molecule adsorption. However, these proposed mechanisms, typically based on models with ideal limit structures, often lacked consistency with the structure and scale of polycrystalline thin films employed in actual experiments. Here, photodetectors utilizing monolayer PtSe_(2) ribbons were designed, demonstrating a significant NPC effect upon exposure to visible light in atmospheric conditions, with device resistance increasing to over threefold the initial state. Under vacuum conditions, the device demonstrated PPC characteristics. Density functional theory calculations indicated that oxygen molecules physically adsorbed at the edges of PtSe_(2) ribbons were integral. Laser irradiation prompted the detachment of oxygen molecules from the ribbon’s edges, leading to a decreased carrier concentration in channel conductivity. The abundant edge sites of the ribbons endowed the photodetectors with a pronounced NPC response. This study diverted from traditional multilayer PtSe_(2) films to explore monolayer PtSe_(2) ribbons. These ribbons, as limit structures, offered a more fundamental insight into the intrinsic photoconductivity properties of PtSe_(2). Photodetectors employing PtSe_(2) ribbons presented novel application prospects in low-power photodetection, gas detection, and additional fields.

关 键 词：platinum diselenide PHOTODETECTOR negative photoconductivity positive photoconductivity photoinduced desorption 

分 类 号：TN21[电子电信—物理电子学]