| 초록 |
Quantum dots have been drawn attention in the field of optoelectronics such as light-emitting devices and displays due to their high color purity, tunable emission wavelengths, and high photoluminescence quantum yield. In particular, carbon quantum dots (CQDs) have advantages such as good biocompatibility, low toxicity and eco-friendly. Herein, nitrogen-doped CQDs (NCQDs) were synthesized by using citric acid and urea as a precursor, followed by diluted sulfuric acid treatment (1 M and 3 M). Elemental analysis by X-ray photoelectron spectroscopy analysis confirms that the changes the composition of carbon and oxygen included functional groups on NCQDs, resulting in increase in the amount of oxygen after acid treatment. The photoluminescence emission of NCQDs is blue-shifted from 440 nm to 375 nm. Moreover, the time resolved-photoluminescence spectra showed the lifetime increased from 2.33 ns to 2.93 ns when the concentration of sulfuric acid is increased from 1 M to 3 M. In sum, the NCQDs with acid treatment might be suitable for the use in blue-light source in quantum dot-light emitting devices (QD-LED), which will be fabricated as blue-light emission LED device in the future |
