(A) study on control of wetting properties of liquid metal for stretchable electrode and its applications

Abstract

Stretchable electrodes are essential components for next-generation electronic devices such as stretchable solar cells, stretchable light emitting diodes, stretchable displays, and wearable devices. Liquid metals have emerged as a promising candidate material for stretchable electrodes because of their remarkable electrical conductivity and negligible Young’s modulus. However, forming thin films with liquid metals is challenging due to their high surface tension. Herein, we introduce a novel liquid metal stretchable electrode architecture (i.e., indium/metallic-interlayer/gallium, InMiG). The metallic-interlayer enhances the electrical conductivity and provides high wettability to gallium, resulting in a smooth and uniform film. The InMiG electrode displays low sheet resistance (<1 Ω/sq) and outstanding stretchability with resistance increasing by 1.9-fold at 100 % strain. In addition, the intrinsically stretchable organic solar cells incorporating the InMiG electrode achieve enhancement of mechanical stability through improving adhesion between top electrode and photoactive layer. Furthermore, the solar cell achieves a high power conversion efficiency of 14.6 % by elevating charge extraction speed of the device.