Anomalous temperature coefficient of resistance in graphene nanowalls/polymer films and applications in infrared photodetectors

Graphene nanowalls (GNWs) exhibit outstanding optoelectronic properties due to their peculiar structure, which makes them a great potential in infrared (IR) detection. Herein, a novel IR detector that is composed of polydimethylsiloxane (PDMS) and designed based on GIWs is demonstrated. Such detector possesses an anomalous temperature coefficient of resistance of 180% K-1 and a relatively high change rate of current (up to 16%) under IR radiation from the human body. It primarily attributes to the ultra-high IR absorption of the GNWs and large coefficient of thermal expansion of PDMS. In addition, the GNW/PDMS device possesses excellent detection performance in the IR region with a responsivity of similar to 1.15 mA W-1 The calculated detectivity can reach 1.07 x 10(8) cm Eta z(1 / 2) W-1 , which is one or two orders of ma nitude larger than that of the traditional carbon-based IR detectors. The significant performance indicates that the GNW/PDMS-based devices reveal a novel design concept. and promising applications for the future new-generation IR photodetectors.