Cross-Aligned Silver Nanowires With Broad-Spectrum High Transmittance and Conductivity for Photodetectors

Transparent conductive films (TCFs) with low sheet resistance and high optical transmittance in the visible and infrared regions are essential components of a wide range of optoelectronic devices. Silver nanowires (AgNWs) have attracted significant attention due to their superior flexibility, conductivity, and transparency. However, TCFs prepared by commonly used film-forming methods such as spin coating suffer from a trade-off between conductivity and transmittance, which results in diminished device performance. Here, we report a layer-by-layer agitation-assisted alignment technique to fabricate highly aligned AgNWs films for transparent electrodes. The effects of solution concentration, rotation speed, and treatment time on the morphology, transmittance, and sheet resistance of the aligned AgNWs films were investigated systematically. Compared with randomly distributed AgNWs, optoelectronic performance was greatly improved, and the final film had a transmittance of 91.07% at 550 nm and a sheet resistance of $27.5~\Omega $ /sq. Research findings indicate that optimized AgNW electrodes can be successfully utilized to fabricate high-performance silicon-based photodetectors. Compared with previous designs, these detectors exhibit a 13.3% increase in the external quantum efficiency (EQE) at a wavelength of 850 nm. This study offers a low-cost and simple method for aligned AgNWs films, which has great potential for use in optoelectronic devices.