Fig. 5: Experimental demonstration of spatial temperature modulation of a Gr-FET.
From: Electrically programmable pixelated coherent mid-infrared thermal emission
a Preliminary sweep of drain current versus gate voltage \({I}_{d}\) -\({V}_{g}\) under a drain voltage \({V}_{d}=50\,{{{\rm{mV}}}}\), where the source electrode is grounded. The low \({V}_{d}\) confirms almost equal potential between the source and drain electrodes, allowing the determination of the Dirac voltage \({V}_{{{{\rm{Dirac}}}}}=-2\,{{{\rm{V}}}}\) for the Gr-FET. b Local resistivity \(\rho\) along the graphene channel \(L=120\,{{\upmu }}{{{\rm{m}}}}\) under different gate voltages. The vertical dash lines represent the positions of maximum local resistivity. The gray shaded areas represent regions outside the graphene channel. c SEM image (scale bar: \(50\,{{\upmu }}{{{\rm{m}}}}\)) showing two pixels with the same resonant emissivity on a single bottom gate electrode. d–f Continuous spatial temperature modulation under \({V}_{d}=30\,{{{\rm{V}}}}\). Thermal mapping images (scale bars: \(50\,{{\upmu }}{{{\rm{m}}}}\)) exhibit the hot spot control by aligning \({V}_{g}\). The dash lines indicate the Dirac point positions \({x}_{0}\).
