Extended Data Figure 4: Gate-dependent SHG spectroscopy of monolayer and bilayer 2H MoTe2.
From: Structural phase transition in monolayer MoTe2 driven by electrostatic doping
a, The SHG intensity of monolayer MoTe2 displays notable hysteresis during forward and backward alteration of the positive top gate (thereby altering the doping of the sample with electrons). The large variation in SHG intensity results mainly from a change in inversion symmetry during phase transition. b, The SHG intensity of a bilayer sample shows no hysteresis under sweeping of the top gate bias. c, Doping with holes (that is, by applying a negative top gate voltage) into 2H monolayer MoTe2 slightly increases the SHG intensity by 1.5 times; a reserve gate sweep shows no hysteresis.
