To gain insights into the crystallographic information, we collected grazingincidence wide-angle X-ray scattering (GIWAXS) patterns of the quasi-2D HP films (Figure ). We apply three different incidence angles, 0.1, 0.2 and 0.5 o , where the small and large angles majorly reflect the crystallographic information of the foremost surface and the bulk interior of the films, respectively. This allows us to explore the progressive change in phase emergence behaviors along the vertical directions.