Microcavity-Integrated Carbon Nanotube Photodetectors

• Published in: ACS nano Vol. 10; no. 7; pp. 6963 - 6971
• Main Authors: Liang, Shuang, Ma, Ze, Wu, Gongtao, Wei, Nan, Huang, Le, Huang, Huixin, Liu, Huaping, Wang, Sheng, Peng, Lian-Mao
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 26.07.2016
• Subjects: carbon nanotube; microcavity; photodetector; photocurrent; Schottky barrier
• ISSN: 1936-0851; 1936-086X
• DOI: 10.1021/acsnano.6b02898

Carbon nanotubes (CNTs) are considered to be highly promising nanomaterials for multiwavelength, room-temperature infrared detection applications. Here, we demonstrate a single-tube diode photodetector monolithically integrated with a Fabry–Pérot microcavity. A ∼6-fold enhanced optical absorption can be achieved, because of the confined effect of the designed optical mode. Furthermore, taking advantage of Van-Hove-singularity band structures in CNTs, we open the possibility of developing chirality-specific (n,m) CNT-film-based signal detectors. Utilizing a concept of the “resonance and off-resonance” cavity, we achieved cavity-integrated chirality-sorted CNT-film detectors working at zero bias and resonance-allowed mode, for specific target signal detection. The detectors exhibited a higher suppression ratio until a power density of 0.07 W cm–2 and photocurrent of 5 pA, and the spectral full width at half-maximum is ∼33 nm at a signal wavelength of 1200 nm. Further, with multiple array detectors aiming at different target signals integrated on a chip, a multiwavelength signal detector system can be expected to have applications in the fields of monitoring, biosensing, color imaging, signal capture, and on-chip or space information transfers. The approach can also bring other nanomaterials into on-chip or information optoelectronics, regardless of the available doping polarity.