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Purpose: This study aims to present an efficient and reliable graphene nanoplatelets (GNPs)-based temperature sensor. Design/methodology/approach: A high-quality dispersion of GNPs was dropped by casting method on platinum electrodes deposited on a polyethylene terephthalate (PET) substrate. The GNPs were characterized by scanning electron microscope, Raman spectroscopy and X-ray diffraction spectra to ensure its purity and quality. The temperature sensing behavior of the fabricated sensor was examined by subjecting it to different temperatures, range from room temperature (RT) to 150 °C. Findings: Excellent resistance linearity with temperature change was achieved. Temperature coefficient of resistance of the fabricated sensor was calculated as 1.4 × 10–3°C. The sensor also showed excellent repeatability and stability for the measured temperature range. Good response and recovery times were evaluated at all the measured temperatures. With measuring the sensor response, the ambient temperature can be determined. Originality/value: The present work presents a new simply and low cost fabricated temperature sensor based on GNPs working at a wide temperature range. [ABSTRACT FROM AUTHOR]

[Display omitted] • In-situ fast processing technique for heteroatom doping of flexible GO films. • Pristine, N, and SN doped laser reduced graphene oxide for planar supercapacitors. • SN-LrGO interdigitated planar SC exhibits an areal capacitance of 13.8 mFcm−2. • Fabricated SCs show long lifespan with more than 90% retention after 2000 cycles. • Series and parallel combinations of SN-LrGO PSCs are investigated. A novel, scalable, single-step and low-synthesis temperature fabrication approach is proposed for real-time doping, reduction, and patterning of graphene oxide-based films supported on flexible polyethylene terephthalate (PET) substrate using a CO2 Laser system. Laser reduced graphene oxide (LrGO), nitrogen-doped laser reduced graphene oxide (N-LrGO), and sulfur-nitrogen co-doped laser reduced graphene oxide (SN-LrGO) planar supercapacitors (PSCs) are readily fabricated with the proposed approach. Structural and elemental characterizations prove the successful integration of nitrogen and sulfur atoms into the graphene framework with high contents up to 3.71 at% N and 1.82 at% S, and at a low density of structural defects. An areal capacitance as high as 13.8 mF cm−2 at 10 mV s−1 and a maximum power density of 151.7 mW cm−3 at an energy density of 0.152 mWh cm−3 is achieved by SN-LrGO PSC composed of 10 interdigitated fingers with an excellent retention rate after 2000 charging/discharging cycles at 0.125 mA cm−2. Furthermore, higher operating voltage window and current ratings are easily achieved via series and parallel combinations of SN-LrGO PSCs directly on the same substrate. This manifests the versatility of the proposed approach for producing flexible and high-performance graphene-based electrochemical storage devices. [ABSTRACT FROM AUTHOR]