플렉스블 그래핀 투명전극의 대면적 플라즈마 패터닝 방법 개발

Abstract

2차원 탄소 구조체로 알려진 그래핀은 ITO를 대체할 수 있는 투명전극 재료로써 플렉스블 전자소자 응용분야에 주목 받는 물질이다. 최근 플렉스블한 그래핀 전극 제조 방법과 생산 기술에 대한 연구가 진행되고 있지만, 그래핀의 대량 생산과 플라스틱 기판에서의 균일한 패턴 제작에 관한 문제로 인해 플렉스블 전극으로의 활용에 어려움을 겪고 있다. 본 연구에서는, CCP 시스템을 기반으로 한 산소 플라즈마 기술을 이용하여 플렉스블하고 투명한 그래핀 전극의 대면적 제조 방법을 보고하였다. 친환경 환원제인 아스코브르산(비타민C)을 이용하여 용액 기반의 그래핀 대량 생산 방법을 제안하였으며, CCP 시스템에서 생성된 산소 플라즈마를 이용하여 그래핀 전극을 플렉스블 기판상에서 미세 패터닝하는 기술을 개발하였다. 제작된 그래핀 전극은 80 S∙cm-1의 높은 전도도와 76%의 우수한 투과도를 나타내었고, ±175도까지 필름을 변형시키는 휘어짐 테스트와 반복적인 구부림에도 안정적인 전류신호와 전도도를 유지하였다. 또한 위의 방법으로 패턴 된 그래핀 필름 위에 LED 회로를 구성하여, 플렉스블 전자소자 응용을 위한 투명 전극으로써의 가능성을 확인하였다.|Graphene, a two-dimensional carbon material, has attracted significant interest for applications in flexible electronics as an alternative transparent electrode to indium tin oxide. However, it still remains a challenge to develop a simple, reproducible, and controllable fabrication technique for producing homogeneous large-scale graphene films and creating uniform patterns with desired shapes at defined positions. Here, we present a simple route to scalable fabrication of flexible transparent graphene electrodes using an oxygen plasma etching technique in a capacitively coupled plasma (CCP) system. Ascorbic acid-assisted chemical reduction enables the large-scale production of graphene with solution-based processability. Oxygen plasma in the CCP system facilitates the reproducible patterning of graphene electrodes, which allows controllable feature sizes and shapes on flexible plastic substrates. The resulting graphene electrode exhibits a high conductivity of 80 S∙cm-1 and a transparency of 76%, and retains excellent flexibility upon hard bending at an angle of ±175° and after repeated bending cycles. A simple LED circuit integrated on the patterned graphene film demonstrates the feasibility of graphene electrodes for use in flexible transparent electrodes.; Graphene, a two-dimensional carbon material, has attracted significant interest for applications in flexible electronics as an alternative transparent electrode to indium tin oxide. However, it still remains a challenge to develop a simple, reproducible, and controllable fabrication technique for producing homogeneous large-scale graphene films and creating uniform patterns with desired shapes at defined positions. Here, we present a simple route to scalable fabrication of flexible transparent graphene electrodes using an oxygen plasma etching technique in a capacitively coupled plasma (CCP) system. Ascorbic acid-assisted chemical reduction enables the large-scale production of graphene with solution-based processability. Oxygen plasma in the CCP system facilitates the reproducible patterning of graphene electrodes, which allows controllable feature sizes and shapes on flexible plastic substrates. The resulting graphene electrode exhibits a high conductivity of 80 S∙cm-1 and a transparency of 76%, and retains excellent flexibility upon hard bending at an angle of ±175° and after repeated bending cycles. A simple LED circuit integrated on the patterned graphene film demonstrates the feasibility of graphene electrodes for use in flexible transparent electrodes.