Browsing by Author "Chiou, Chung Chin"

Now showing 1 - 2 of 2

FLEXIBLE AND STRETCHABLE OPTOELECTRONIC DEVICES USING GRAPHENE
(2019-01-01)
Chiou, Chung Chin
;
Marinova, Vera
;
Petrov, Stefan
;
Fidanova, Cvetelina
;
Angelova, Ina
In this paper we demonstrate flexible polymer dispersed liquid crystal (PDLC) devices using graphene as transparent conductive electrodes on polyethylene terephthalate (PET) substrate. Graphene was grown by Low Pressure Chemical Vapor Deposition (LPCVD) technique and characterized by Raman analysis, optical and electrical measurements. Several graphene-based PDLC devices have been fabricated and their electro-optical characteristics, response time and bending ability were measured and discussed. The results support the graphene promising features for integration in flexible optoelectronics.
Flexible light valves using polymer-dispersed liquid crystals and TiO2/Ag/TiO2 multilayers
(2019-06-10)
Chiou, Chung Chin
;
Hsu, Fan Hsi
;
Petrov, Stefan
;
Marinova, Vera
;
Dikov, Hristosko
The era of flexible optoelectronics demands development of wearable and bendable structures, foldable touch screens, paper-like displays, and curved and flexible solid-state lighting devices. Here, we demonstrate the fabrication of highly flexible light valves using polymer-dispersed liquid crystal (PDLC) and TiO2/Ag/TiO2 transparent conductive films. TiO2/Ag/TiO2 multilayers were prepared by magnetron sputtering technique on polyethylene terephthalate (PET) substrates at room temperature. By keeping the equivalent TiO2 layers and varying the deposition time of the Ag layer, proper metal nanograins on TiO2 planar plane were formed, providing the best tradeoff between the transmittance, sheet resistance and bending ability. The results are validated by numerical simulations that suggest the best match between the deposition time and individual layer thickness. Based on the performed characteristics of TiO2/Ag/TiO2/PET structures, several flexible light valves are fabricated and characterized. The sheet resistance values of TiO2/Ag/TiO2/PET remain unchanged over 1000 bending cycles. The measured driving voltage and response time values open great potential of TiO2/Ag/TiO2/PET for integration into next-generation ITO-free flexible and stretchable devices. (C) 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement