Ultraviolet photodetectors with high photosensitivity based on type-II ZnS/SnO2 core/shell heterostructured ribbons

作者：Huang, Xing; Yu, Yong-Qiang; Xia, Jing; Fan, Hua; Wang, Lei; Willinger, Marc-Georg^*; Yang, Xiao-Ping; Jiang, Yang; Zhang, Tie-Rui; Meng, Xiang-Min

来源：Nanoscale, 2015, 7(12): 5311-5319.

DOI：10.1039/c5nr00150a

• ZNS/ZNO BIAXIAL NANOBELT
• FIELD-EFFECT TRANSISTORS
• HIGH-PERFORMANCE
• PHOTOVOLTAIC APPLICATIONS
• ZNS NANOWIRES
• SNO2 NANOWIRE
• ZNO/ZNS
• NANOCRYSTALS
• GROWTH
• ARRAYS

Semiconducting heterostructures with type-II band structure have attracted much attention due to their novel physical properties and wide applications in optoelectronics. Herein, we report, for the first time, a controlled synthesis of type-II ZnS/SnO2 heterostructured ribbon composed of SnO2 nanoparticles that uniformly cover the surface of ZnS ribbon via a simple and versatile thermal evaporation approach. Structural analysis indicated that the majority of SnO2 nanoparticles have an equivalent zone axis, i.e., <-313 > of rutile SnO2, which is perpendicular to +/-(2-1-10) facets (top/down surfaces) of ZnS ribbon. For those SnO2 nanoparticles decorated on +/-(01-10) facets (side surfaces) of ZnS ribbon, an epitaxial relationship of (01-10)(ZnO)//(020)(SnO2) and [2-1-10](ZnO)//[001](SnO2) was identified. To explore their electronic and optoelectronic properties, we constructed field-effect transistors from as-prepared new heterostructures, which exhibited an n-type characteristic with an on/off ratio of similar to 10(3) and a fast carrier mobility of similar to 33.2 cm(2) V-1 s(-1). Owing to the spatial separation of photogenerated electron-hole pairs from type-II band alignment together with the good contacts between electrodes and ribbon, the resultant photo-detector showed excellent photoresponse properties, including large photocurrent, high sensitivity (external quantum efficiency as high as similar to 2.4 x 10(7)%), good stability and reproducibility, and relatively fast response speed. Our results suggest great potential of ZnS/SnO2 heterostructures for efficient UV light sensing, and, more importantly, signify the advantages of type-II semiconducting heterostructures for construction of high-performance nano-photodetectors.

• 出版日期2015
• 单位中国科学院理化技术研究所; 合肥工业大学