Spectral-selective near-infrared photothermal detector enabled by integrating graphene-Au nanorods hybrid on a thermistor

Abstract

Near-infrared (NIR) detectors with high sensitivity and spectral selectivity are highly desired in various applications. In this work, a photothermal detector with high NIR sensitivity and spectral selectivity was developed by simply modifying a photothermal layer of reduced graphene oxide-Au nanorods (rGO-AuNRs) hybrid on a thermistor, which can convert the light energy into heat and reflect as resistance changes of a thermistor. Owing to the plasmon coupling of the two materials, the obtained rGO-AuNRs hybrid not only has remarkable photothermal conversion efficiency but also exhibits dependence on spectral response. Thus, benefiting from the excellent performance of the hybrid, the fabricated detector is sensitive to illumination in the wavelength range from 700 to 1000 nm with the highest photoresponsivity of 2.50 × 105 Ω·W−1. The photothermal detector presented in this work will provide a simple and inexpensive alternative for NIR detector development.