Browsing by Author "Lee, Hsiao-Chin"

Now showing 1 - 4 of 4

A demonstration of solid-state white light-emitting electrochemical cells using the integrated on-chip plasmonic notch filters
(2016)
Lee, Ya-Ju
;
Lin, Chia-Ching
;
Lee, Hsiao-Chin
;
Yao, Yung-Chi
;
Sarma, Monima
In this study, we demonstrate solid-state white light-emitting electrochemical cells (LECs) using an integrated plasmonic notch filter to tailor the electroluminescence (EL) spectrum of non-doped blue-green emissive material. The plasmonic notch filter is composed of randomly distributed silver nanoparticles (Ag-NPs) embedded in the anode contact of indium tin oxide (ITO). This plasmonic notch filter strongly absorbs green light due to local surface plasmon (LSP) resonance of the Ag-NPs embedded in ITO. Thus, the emission green light of the solid-state LEC is strongly suppressed, leaving the blue and red light output to generate a white EL emission. Moreover, the duration of white EL can be maintained for a longer time under operation, which overcomes the issues regarding the short lifetime of white EL generated by the microcavity effect. In addition, the Ag-NPs can be readily fabricated by the thermal annealing of Ag film, which is compatible with current fabrication technologies typically used in light-emitting diode (LED) industry. Therefore, solid-state white LECs using an integrated on-chip plasmonic notch filter have great potential for applications in solid-state lighting.
Adjusting Color Temperature of Electroluminescence from White Light-Emitting Electrochemical Cells by Laser-Scanned Annealing of Nanoparticles
(2017-01-01)
Lee, Hsiao-Chin
;
Chiang, Chien-Ming Fan
;
Wu, Po-Yi
;
Yao, Yung-Chi
;
Sarma, Monima
Color temperature of electroluminescence from white light-emitting electrochemical cells can be adjusted by locally laser-scanned thermal annealing on a semi-continuous thin Ag film embedded between indium tin oxide anode and glass substrate. The proposed technique offers programmable versatility to control white electroluminescence and is compatible with display manufacturing technologies.
Dynamically tuning the correlated color temperature of white light-emitting electrochemical cells with electrochromic filters
(2017-09-01)
Chiou, Bo-Ruei
;
Lee, Hsiao-Chin
;
Jang, Yea-Fen
;
Yang, Zu-Po
;
Wang, Yao-Chin
Recently, white solid-state light-emitting electrochemical cells (LECs) have drawn great attention since they exhibit advantages such as low-voltage operation, compatibility with solution processes and employing inert cathode metals. Since different correlated color temperatures (CCTs) of background illumination are necessary for various lighting applications, a real-time tunable CCT of white LECs would be highly desired in modern smart lighting systems. In this work, a widely and dynamically tuning CCT (>10000 K) of white LEC is demonstrated by employing an electrochromic device (ECD) as a real-time controllable color filter. By increasing the applied bias on the ECD to attenuate more the red parts of white EL from the white LEC, the LEC-based white light source becomes more bluish and, in consequence, shows higher CCT. This proposed LEC-based white light source with the characteristics of wide CCT range and real-time tunability is suitable for most lighting applications and modern smart lighting systems. (C) 2017 Elsevier B.V. All rights reserved.
Laser-Scanned Programmable Color Temperature of Electroluminescence from White Light-Emitting Electrochemical Cells
(2016-11-23)
Lee, Hsiao-Chin
;
Chiang, Chien-Ming Fan
;
Wu, Po-Yi
;
Yao, Yung-Chi
;
Sarma, Monima
Recently, the control of correlated color temperature (CCT) of artificial solid-state white-light sources starts to attract more attention since CTs affect human physiology and health profoundly. In this work, we proposed and demonstrated a method that can widely tune the CCTs of electroluminescence (EL) from white-light-emitting electrochemical cells (LECs) by employing plasmonic filters. These integrated on-chip plasmonic filters are composed of semicontinuous thin Ag film or Ag nanoparticles (NPs) both included in the indium tin oxide anode contact, which have different characteristics of plasmonic resonant absorptions that can tune the EL spectra of white LECs. The CCTs of EL from white LECs integrated with semicontinuous thin Ag film and randomly distributed Ag NPs are 5778 and 2350 K, respectively. A commercially available laser scanning system was used to locally thermal anneal the semicontinuous thin Ag film to form the randomly distributed Ag NPs on the scanned areas. Hence, these two kinds of filters can be integrated on the same chip of white LEC, giving more freedom to control the CCTs of white EL and more potential applications. In addition, the laser scanning system used here is quite often used in display manufactures so that our proposed method can be immediately adopted by the light-emitting diode industry.