. Thereby, even the lowest voltage already yields a transit time of 1 ns with a moderate mobility estimated from few layer flakes. Accordingly, higher voltages would only be even faster than this time. Figure shows the variation of the channel length for the bilayer and the few layer flake. The idea behind a shortening of the electrode gap is again an acceleration of the detector due to the decrease of resistance, due to less material 3 and a shortening of the transit time . For the two flakes shown here, it can be seen, that the shortening shows an ambiguous trend and the main limiting mechanism for the steady state measurements still seems to be the photoresistance, as can be seen in Figure .