posted on 2024-01-27, 14:05authored byMehdi Zarei, Mingxuan Li, Elizabeth E. Medvedeva, Sooraj Sharma, Jungtaek Kim, Zefan Shao, S. Brett Walker, Melbs LeMieux, Qihan Liu, Paul W. Leu
A facile and novel
fabrication method is demonstrated for creating
flexible poly(ethylene terephthalate) (PET)-embedded silver meshes
using crack lithography, reactive ion etching (RIE), and reactive
silver ink. The crack width and spacing in a waterborne acrylic emulsion
polymer are controlled by the thickness of the polymer and the applied
stress due to heating and evaporation. Our innovative fabrication
technique eliminates the need for sputtering and ensures stronger
adhesion of the metal meshes to the PET substrate. Crack trench depths
over 5 μm and line widths under 5 μm have been achieved.
As a transparent electrode, our flexible embedded Ag meshes exhibit
a visible transmission of 91.3% and sheet resistance of 0.54 Ω/sq
as well as 93.7% and 1.4 Ω/sq. This performance corresponds
to figures of merit (σDC/σOP) of
7500 and 4070, respectively. For transparent electromagnetic interference
(EMI) shielding, the metal meshes achieve a shielding efficiency (SE)
of 42 dB with 91.3% visible transmission and an EMI SE of 37.4 dB
with 93.7% visible transmission. We demonstrate the highest transparent
electrode performance of crack lithography approaches in the literature
and the highest flexible transparent EMI shielding performance of
all fabrication approaches in the literature. These metal meshes may
have applications in transparent electrodes, EMI shielding, solar
cells, and organic light-emitting diodes.