Abstract
Achieving high gain in a photodetector is critical to detect weak light fields because of the need to amplify the signal. Here, we report the observation of a gain exceeding 109 for a phototransistor composed of an array of aligned semiconducting carbon nanotubes functionalized with a nanoscale layer of poly(3-hexylthiophene-2,5-diyl) (P3HT). In contrast to the expectation based on simple band alignments, the phototransistor operates by transferring holes between the P3HT and the CNT, trapping negative charge near the nanotubes. This mechanism leads to an integrating detector that is shown to detect as little as 490 aW and to resolve as few as 8-13 photons/nanotube at room temperature. A detailed experimental and theoretical investigation of the mechanism shows that the phototransistor is most sensitive when prepared in a nonequilibrium state.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.