Fig. 3: MIR photoluminescence spectra of BP–WSe2 heterostructures.
From: Black phosphorus-based van der Waals heterostructures for mid-infrared light-emission applications
a MIR PL spectra of thin-film BP (blue lines) and BP–WSe2 heterostructures (orange lines) at 80 K. b Schematic band diagram of BP–WSe2 heterostructures. The dashed line denotes the Fermi energy of BP and WSe2. c MIR PL enhancement in BP–WSe2 heterostructures as a function of thickness. The solid line is a guide line. d Polarization-resolved MIR PL spectra for the BP–WSe2 heterostructure with 5-nm-thick BP. The solid line is the fitting curve obtained using the equation I= (Imax − Imin) cos2θ + Imin. Here, θ is the polarization angle referenced to the armchair axis of BP, and Imax and Imin are the PL intensities along the armchair- and zigzag axes, respectively
