Figure 3.
Determination of the carrier-multiplication efficiency. (a) The peak value of THz photoconductivity of 2H-MoTe2 as a function of absorbed photon density for different pump photon energies. The solid lines are linear fittings to the data; three dashed lines represent CM quantum yield of 100%, 200%, and 300%, to guide the eye. (b) The photoconductivity at a given absorbed photon density for varied photon energies (hν, bottom x-axis) and the ratio of hν/Eg (top x-axis). The data are rescaled to match 100% quantum yield of charge generation for the sub-2Eg excitations. The model (dash-dotted lines) is discussed in the main text. (c) Schematic drawing of band structure and carrier multiplication in indirect semiconducting few-layer MoTe2.