Fig. 2: Optical properties of the WS2(1−x)Se2x (x = 0.8) sample.
From: Indirect to direct band gap crossover in two-dimensional WS2(1−x)Se2x alloys
a, e Optical images obtained from two distinct triangular and hexagonal flakes, showing that the 1, 2 and 3 ML regions present different optical contrasts. b, f PL intensity maps and c, g peak position maps acquired on the triangular and hexagonal flakes of a, e with a 532 nm laser excitation. d, h Typical PL spectra obtained from different positions on the flakes of a, e indicated by 1–4 in (a), corresponding to 1, 2, 3 and 4 ML, respectively.
