Potassium doping: Tuning the optical properties of graphene quantum dots

Fuli Qian, Xueming Li, Libin Tang, Sin Ki Lai, Chaoyu Lu, Shu Ping Lau

Research output: Journal article publicationJournal articleAcademic researchpeer-review

45 Citations (Scopus)


Doping with hetero-atoms is an effective way to tune the properties of graphene quantum dots (GQDs). Here, potassium-doped GQDs (K-GQDs) are synthesized by a one-pot hydrothermal treatment of sucrose and potassium hydroxide solution. Optical properties of the GQDs are altered as a result of K-doping. The absorption peaks exhibit a blue shift. Multiple photoluminescence (PL) peaks are observed as the excitation wavelength is varied from 380 nm to 620 nm. New energy levels are introduced into the K-GQDs and provide alternative electron transition pathways. The maximum PL intensity of the K-GQDs is obtained at an excitation wavelength of 480 nm which is distinct from the undoped GQDs (375 nm). The strong PL of the K-GQDs at the longer emission wavelengths is expected to make K-GQDs more suitable for bioimaging and optoelectronic applications.
Original languageEnglish
Article number075116
JournalAIP Advances
Issue number7
Publication statusPublished - 1 Jul 2016

ASJC Scopus subject areas

  • Physics and Astronomy(all)


Dive into the research topics of 'Potassium doping: Tuning the optical properties of graphene quantum dots'. Together they form a unique fingerprint.

Cite this