Category Archives: Reflective display

Fully Screen-Printed, Large-Area, and Flexible Active-Matrix Electrochromic Displays Using Carbon Nanotube Thin-Film Transistors

Journal: American Chemical Society NANO

Publication date: 2016.10.17

Summarized by Sejin Kim


– The fabrication process of the fully screen-printed flexible active-matrix electrochromic display using SWCNT(single-walled CNT) TFTs.


Fig. 1


Fig. 2

v. Figure (a)

  1. High-purity semiconducting SWCNTs were incubated on a 5 × cm2 PET substrate.
  2. The printing of silver source and drain electrodes and data lines.
  3. The printing of a BTO layer (barium titanate/gate dielectric) on the channel region of each TFT.

v. Figure (b)

  1. Printed BTO layer was used as a hard mask for etching to remove the unwanted SWCNTs outside the TFT region.
  2. Then another BTO layer was printed as a passivation layer to protect the data lines and the ground lines.

v. Figure (c)-(e)

  1.  Scan lines, ground lines, PEDOT:PSS layer, and electrolyte were screen-printed sequentially+.


– The fully screen-printed flexible electrochromic cells.

Fig. 3

v. The switching time of this electrochromic cells : 2−5 s

v. The printed EC cell operates reliably under bending.

v. Negligible degradation of the electrical performance after 7 days in air.


– The control of coloration and retention behavior by changing VScan and VData

Fig. 4

v. Vscan = -10V [TFT on], VData = 4V: the oxidation of PEDOT:PSS-> [transparent state]

v. Vscan = 10V [TFT off], VData = 4V: the pixel color is retained.

v. Vscan = -10V [TFT on], VData = -4V à the reduction of PEDOT:PSS -> [dark-blue state]

v. Vscan = 10V [TFT off], VData = – 4V: the pixel color is retained.


Fig. 5