• 文献标题:   Ultralow-Transition-Energy Organic Complex on Graphene for High-Performance Shortwave Infrared Photodetection
  • 文献类型:   Article
  • 作  者:   IQBAL MA, LIAQAT A, HUSSAIN S, WANG XS, TAHIR M, UROOJ Z, XIE LM
  • 作者关键词:   charge transfer complex, graphene, photodetection, photogating, shortwave infrared region
  • 出版物名称:   ADVANCED MATERIALS
  • ISSN:   0935-9648 EI 1521-4095
  • 通讯作者地址:   Natl Ctr Nanosci Technol
  • 被引频次:   1
  • DOI:   10.1002/adma.202002628 EA JUL 2020
  • 出版年:   2020

▎ 摘  要

Room-temperature, high-sensitivity, and broadband photodetection up to the shortwave infrared (SWIR) region is extremely significant for a wide variety of optoelectronic applications, including contamination identification, thermal imaging, night vision, agricultural inspection, and atmospheric remote sensing. Small-bandgap semiconductor-based SWIR photodetectors generally require deep cooling to suppress thermally generated charge carriers to achieve increased sensitivity. Meanwhile, the photogating effect can provide an alternative way to achieve superior photosensitivity without the need for cooling. The optical photogating effect originates from charge trapping of photoinduced carriers at defects or interfaces, resulting in an extremely high photogain (10(6)or higher). Here, a highly sensitive SWIR hybrid photodetector, fabricated by integrating an organic charge transfer complex on a graphene transistor, is reported. The organic charge transfer complex (tetrathiafulvalene-chloranil) has an exceptional low-energy intermolecular electronic transition down to 0.5 eV, with the aim of achieving efficient SWIR absorption for wavelengths greater than 2 mu m. The photogating effect at the organic complex and graphene interface enables an extremely high photogain and a high detectivity of approximate to 10(13)Jones, along with a response time of 8 ms, at room temperature for a wavelength of 2 mu m.