Park, Sang Hyun Hong, Ara Kim, Jong-Hoon Yang, Heesun Lee, Kwangyeol Jang, Ho Seong 2024-01-20T07:30:19Z 2024-01-20T07:30:19Z 2021-09-04 2015-04-01 1944-8244 https://pubs.kist.re.kr/handle/201004/125560 In this study, we report bright yellow-green-emitting CuInS2 (CIS)-based quantum dots (QDs) and two-band white light-emitting diodes (LEDs) using them. To achieve high quantum efficiency (QE) of yellow-green-emitting CIS QDs, core/shell/shell strategy was introduced to high quality CIS cores (QE = 31.7%) synthesized by using metal-oleate precursors and 1-dodecanethiol. The CIS/ZnS/ZnS QDs showed a high QE of 80.0% and a peak wavelength of 559 nm under the excitation of 450 nm, which is well matched with dominant wavelength of blue LEDs. The formation of core/shell/shell structure was confirmed by X-ray diffraction, transmission electron microscopy, and inductively coupled plasma-optical emission spectroscopy analyses. Intense and broad yellow-green emission band of the CIS/ZnS/ZnS is beneficial for bright two-band white light. When the CIS/ZnS/ZnS was coated on the blue LEDs, the fabricated white LED showed bright natural white light (luminous efficacy (?L) = 80.3 lm.W-1, color rendering index (R-a) = 73, correlated color temperature (T-c) = 6140 K). The QD-white LED package showed a high light conversion efficiency of 72.6%. In addition, the CIS/ZnS/ZnS-converted white LED showed relatively stable white light against the variation of forward bias currents of 20-150 mA [color coordinates (x, y) = (0.3320-0.3207, 0.2997-0.2867), R-a = 70-72, T-c = 5497-6375 K]. English American Chemical Society SEMICONDUCTOR NANOCRYSTALS PHOSPHOR EFFICIENCY NANOPHOSPHORS PROPERTY DROOP Highly Bright Yellow-Green-Emitting CuInS2 Colloidal Quantum Dots with Core/Shell/Shell Architecture for White Light-Emitting Diodes Article 10.1021/acsami.5b00166 1 ACS Applied Materials & Interfaces, v.7, no.12, pp.6764 - 6771 ACS Applied Materials & Interfaces 7 12 6764 6771 scie scopus 000352246700049 2-s2.0-84926308881 Nanoscience & Nanotechnology Materials Science, Multidisciplinary Science & Technology - Other Topics Materials Science Article SEMICONDUCTOR NANOCRYSTALS PHOSPHOR EFFICIENCY NANOPHOSPHORS PROPERTY DROOP core/shell/shell luminescence quantum dots white LEDs