Electric field-induced breaking behavior of silver nanowire-based transparent and conductive films and their protection

Abstract

Herein, electrical stability of silver nanowire (AgNW)-based transparent and conductive films (TCFs) is studied. It is observed that when a TCF is biased continuously at a given voltage, the electrical current decreases slowly at first and then drops quickly, until reaching zero. Metal-microscope characterization shows that a crack appears after the stability test. Scanning electron microscope (SEM) analysis indicates that the nanowires are welded into particles. As such, breaking behavior appears during the continuous bias process. Thermal imaging tests show that the “Joule effect” occurs simultaneously during the cracking process. In addition, the crack tends to move in parallel with the evaporated pair of electrodes. The electric field-induced breaking behavior could be well understood by the Ohm's law. For a better understanding, multi-physics field simulation works are performed. It is found that the formation process relates closely with the distribution of the electric field. The crack tends to form along a typical isopotential line, while the breaking front lies at the position with the strongest electric field. The breaking behavior could be mitigated to a certain extent by surface modification using polyvinylpyrrolidone (PVP). Fogging-defogging cyclic test is performed. PVP modification is observed to prolong the test rounds by two times, which implies potential anti-fog application of the AgNW-based TCFs.