Fig. 4: Band structures and electrical characterization of α-/β-Te transistors.
From: Phase-engineered synthesis of atomically thin te single crystals with high on-state currents
a, d Bandgaps of α-Te nanosheets (a) and β-Te nanoribbons (d) as a function of the number of atomic layers. The red points denote calculated bandgap values, and the purple balls denote Te atoms. b, c, e, f The drain source current-drain source voltage·(lds-Vds) output curves under various gate voltages from 60 V to -60 V (−10 V step) and the drain source current-gate source voltage·(lds-Vgs) transfer curves under various bias voltages (red, -0.1 V; blue, -0.4 V; green, -0.7 V; purple, −1 V) for the α-Te/WS2 (b, c) and β-Te/WS2 devices (e, f), respectively. The insets show optical images of the α-Te/WS2 (b) and β-Te/WS2 (e) devices with thicknesses of 3.2 nm and 2.1 nm, respectively. Scale bars in (b and e): 2 µm. g AFM image of the α-Te nanosheets and β-Te nanoribbons at different times. Scale bars: 2 µm. h, i Transfer curves of the α-Te (h) and β-Te devices (i) at 0 (red line) and several months (blue line), respectively.
