Fig. 4: Spatial mapping of PL peak position and FWHM in WS2 FETs.
From: Impact of doping and channel inhomogeneities on the stability of industrially fabricated WS2 FETs
a PL peak position maps and b PL peak FWHM maps collected from three WS2 FETs with varying channel areas. Again, as the channel area decreases, the PL emission becomes broader and shifts to lower energies, indicating an increased electron concentration in the channel (i.e., higher n-type doping). Additionally, the maps reveal enhanced n-type doping near the edge metal contacts in the 10 × 10.2 and 10 × 2.2 μm2 devices, and a non-uniform doping profile along the channel width in the 75 × 30.2 μm2 device.
