Position-dependent and millimetre-range photodetection in phototransistors with micrometre-scale graphene on SiC.

The extraordinary optical and electronic properties of graphene make it a promising component of high-performance photodetectors. However, in typical graphene-based photodetectors demonstrated to date, the photoresponse only comes from specific locations near graphene over an area much smaller than the device size. For many optoelectronic device applications, it is desirable to obtain the photoresponse and positional sensitivity over a much larger area.