Fig. 4
From: Accessing valley degree of freedom in bulk Tin(II) sulfide at room temperature
Photoluminescence measurements of SnS. a Deconvolutions of PL peaks under parallel polarization at 817 and 995 nm give clear, opposite trends with respect to sample orientation, demonstrating the identity of the valley positions. b, c Polar plots of PL peak height intensities conducted under parallel polarization for the valleys at 817 and 995 nm, respectively (squares). The single circular data point in each polar plot represents the PL peak height intensities of the corresponding measurements conducted with the second polarizer perpendicular to the incident light when the respective axes are aligned to the excitation polarization. The black dashed arrows connect the two data points before and after the 90° rotation of the second polarizer, showing 95% and 96% decrease in PL intensities at the ΓY and ΓX valleys respectively. These show valley selectivity in the absorption and emission of light
