Bright Mid-Infrared Photoluminescence from Thin-Film Black Phosphorus

Chen Chen, Feng Chen, Xiaolong Chen, Bingchen Deng, Brendan Eng, Daehwan Jung, Qiushi Guo, Shaofan Yuan, Kenji Watanabe, Takashi Taniguchi, Minjoo L. Lee, Fengnian Xia

Research output: Contribution to journalArticle

Abstract

Recently rediscovered layered black phosphorus (BP) provides rich opportunities for investigations of device physics and applications. The band gap of BP is widely tunable by its layer number and a vertical electric field, covering a wide electromagnetic spectral range from visible to mid-infrared. Despite much progress in BP optoelectronics, the fundamental photoluminescence (PL) properties of thin-film BP in mid-infrared have rarely been investigated. Here, we report bright PL emission from thin-film BP (with thickness of 4.5 to 46 nm) from 80 to 300 K. The PL measurements indicate a band gap of 0.308 ± 0.003 eV in 46 nm thick BP at 80 K, and it increases monotonically to 0.334 ± 0.003 eV at 300 K. Such an anomalous blueshift agrees with the previous theoretical and photoconductivity spectroscopy results. However, the observed blueshift of 26 meV from 80 to 300 K is about 60% of the previously reported value. Most importantly, we show that the PL emission intensity from thin-film BP is only a few times weaker than that of an indium arsenide (InAs) multiple quantum well (MQW) structure grown by molecular beam epitaxy. Finally, we report the thickness-dependent PL spectra in thin-film BP in mid-infrared regime. Our work reveals the mid-infrared light emission properties of thin-film BP, suggesting its promising future in tunable mid-infrared light emitting and lasing applications.

Original languageEnglish (US)
Pages (from-to)1488-1493
Number of pages6
JournalNano letters
Volume19
Issue number3
DOIs
StatePublished - Mar 13 2019

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Keywords

  • Black phosphorus
  • anomalous blueshift
  • band gap
  • mid-infrared
  • photoluminescence
  • tunability

ASJC Scopus subject areas

  • Bioengineering
  • Chemistry(all)
  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanical Engineering

Cite this

Chen, C., Chen, F., Chen, X., Deng, B., Eng, B., Jung, D., Guo, Q., Yuan, S., Watanabe, K., Taniguchi, T., Lee, M. L., & Xia, F. (2019). Bright Mid-Infrared Photoluminescence from Thin-Film Black Phosphorus. Nano letters, 19(3), 1488-1493. https://doi.org/10.1021/acs.nanolett.8b04041