화학공학소재연구정보센터
학회 한국재료학회
학술대회 2019년 봄 (05/15 ~ 05/17, 평창 알펜시아 리조트)
권호 25권 1호
발표분야 G. 나노/박막 재료 분과
제목 High on–off ratio, large area CVD-grown graphene phototransistors
초록 Two-dimensional materials have attracted strong interest for their fascinating electronic properties and have shown many advantages in optoelectronic applications. Among two-dimensional materials, graphene has demonstrated promising applications in various types of photodetectors from terahertz to ultraviolet, due to light absorption in broad wavelength range and their ultrahigh carrier mobility. However, graphene’s semimetallic nature would give rise to a large dark current (up to 50–100 uA) and low on–off ratio (less than 2). Here, we demonstrate a new method to enhance the on-off ratio of graphene photodetector with metal-graphene-metal structure. In this phototransistor, an asymmetric metal contact (Titanium and Platinum) design is adopted to provide a strong internal electric-field in the phototransistor channel. Optical microscopy, Raman spectroscopy and atomic force microscopy (AFM) were used to determine optimal etching conditions and observe residues after thermal treatment. The device offers a high on-off, a broad spectral bandwidth and compatibility with CMOS technologies.
저자 이정상1, 인재현1, 주현수1, 김상식2, 이전국1
소속 1한국과학기술(연), 2고려대
키워드 CVD graphene; on–off ratio; large area
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