Fig. 2: Electronic and optical properties of MX2.
From: Phase-matching-free parametric oscillators based on two-dimensional semiconductors
a, b Valence EV(k) and conduction EC(k) energy bands for MoS2, where k is the electron wave-vector and a = 3.19 Å is the lattice parameter. c, d Dependence of the linear surface conductivities of ML-TMDs on c the vacuum wavelength λ (for intrinsic doping EF = 0) and on d the Fermi level EF ensuing from extrinsic doping (at λ = 1.6 μm). e PDC mixing surface conductivities of MoS2 at λ3 = 800 nm as a function of the angular frequency mismatch of down-converted signal and idler waves Δω = ω1 − ω2 rescaled to the pump angular frequency ω3. f Dependence of the real and imaginary parts of the PDC mixing conductivity σ1,3 for MX2 ML-TMDs on the Fermi level EF for λ1 = λ2 = 1.6 μm and λ3 = 0.8 μm.
