Fig. 2: The alignment textures and PL spectra.

a–c Alignment textures, illustrations of the corresponding twisted structures and PL spectra for various rubbing angles R_θ (a R_θ = 60° and b R_θ = 90° without chiral dopant, and c R_θ = 100° with 2.5 wt% of chiral dopant). The PL spectra measured without a circular polarizer, and with LH and RH circular polarizers are presented by black (I_T), red (I_L), and blue (I_R) solid lines, respectively. The dark and bright areas in (b) indicate that RH and LH twist structure, respectively. For the comparison, the spectrum intensities were normalized with respect to the peak intensity without a circular polarizer. d Measured twisted angle of the F8BT layer as a function of the rubbing angle. Open diamonds and filled triangles are measured from the F8BT layers without chiral dopant before and after removing NOA65, respectively. Open squares and filled circles are measured from the F8BT layer blended with 2.5 wt% of S5011 before and after removing NOA65, respectively. e |g_PL| as a function of the twisted angle. The symbols represent experimentally measured values from the CPPL (open squares and filled circles are the values before and after removing NOA65, respectively) and the solid line represents calculated value using the Mueller matrix method. Here, red (red open squares and red filled circles) and green symbols (green open squares and green filled circles) represent the g_PL values of the pure F8BT without the chiral dopant and those of the F8BT with the 2.5 wt% chiral dopant. Here, all scale bars represent 0.5 mm.