Now, researchers at the Ulsan National Institute of Science and Technology (UNIST) have developed a novel approach. This strategy increases the conductivity of the achieved silver nanowire (AgNW) electrodes. Industry experts believe this groundbreaking new technique may be the key to producing a whole new range of small bendable electronic devices. Professor Tae-Hyuk Kwon and his research team in the Department of Chemistry have achieved an important milestone. They recently developed a new process to replace the insulating PVP coating with ethylene glycol (EG). Their findings show an unprecedented 43% decrease in electrical resistance, nearly doubling the conductivity of the electrodes.
Silver nanowires are metallic filaments that are four times thinner than a human hair. Together, they create a superhighway for electricity and pave the way for light to enter. Combined with their tunable porosity and optical properties, this makes them excellent candidates towards the use of GO and rGO as transparent electrodes for EMI applications. In the laboratory, PVP is often employed in the fabrication process to encourage nanowire growth by wrapping around their surfaces. Regrettably, this thermally insulating layer raises electrical resistance, making it difficult for the material to conduct electricity efficiently.
A Novel Solution Process
Now, a multidisciplinary UNIST research team led by Professor Taekyung Kim has developed a more intuitive approach. This new approach trades PVP with ethylene glycol, greatly enhancing the performance of silver nanowires. By employing a simple solution approach, they managed to remove PVP, through which they made EG – a less insulating polymer – the main product. Combined with this strategic tradeoff, electrical resistance was reduced by 43%. It yielded electrodes that functioned optimally even under harsh conditions, withstanding 85°C and 85% humidity.
This breakthrough creates exciting new opportunities for the use of AgNWs in flexible electronics. In addition, the adjusted electrodes showed a small improvement in light transmittance. This advancement opens the door to brighter, more transparent electrodes. As a consequence, their possible uses in widely emerging technologies—from AI to 5G—multiply exponentially.
Enhanced Heating Performance
Besides superior electrical conductivity, the fabricated silver nanowire electrodes showed promising heating performance and features on thin film heating applications. The expansive research team made transparent heaters with improved electrode materials. Compared to conventional AgNW heaters, these novel heaters provided more than 35% improved heating performance. These heaters alarmingly attained temperatures of 140°C to 145°C in as little as six minutes of being turned on. They handily broke the previous record high temperature of 102°C.
This fast heating feature increases efficiency drastically. It unlocks the path to new, faster heating solutions for applications from consumer electronics today to advanced, next-generation systems in the automotive and aerospace industries tomorrow.
Collaborative Research Effort
The successful development of this new coating technique was led through a collaborative effort between specialized experts. Professor Kwon served as the principal investigator for the research team, as well as technical oversight from Dr. Ji Hoon Seo of Korea Electric Power Research Institute (KEPRI). Moreover, Professor EunAe Cho of KAIST and Professor Sang-Won Park of Suwon University provided valuable insights. Their unmatched chemistry and materials science expertise was instrumental in pushing this research forward.
The findings were published in the prestigious journal Angewandte Chemie International Edition, with the article bearing the DOI: 10.1002/anie.202518337. This publication represents a significant advance into the world of transparent conductive materials. It also underscores the incredible possibilities still waiting for future innovators of flexible electronic devices to discover and develop.