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 journalArticlepeer-review


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
Issue number3
StatePublished - Mar 13 2019


  • 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


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