High-performance devices from lab-scale to micro module directed by vertical PbI2 homogeneous growth perovskite films
Abstract
The morphology of the initial PbI 2 film is very pivotal in dictating the uniformity and crystallinity of the resultant perovskite film in the two-step sequential deposition processes. A solution-based induction is introduced to transform PbI 2 clusters into PbI 2 nanowires to achieve controllable morphology of the PbI 2 film. The nanowires act as scaffolds for the subsequent perovskite formation. An in-plane low-angle diffraction detected in the in-situ grazing-incidence small-angle X-ray scattering (GISAXS) for the PbI 2 film indicates the formation of a periodically arranged ordered structure. The PbI 2 nanowires facilitate the ion-exchange process, markedly improving the homogeneity and orientation of the perovskite films, which is confirmed by the in-situ grazing-incidence wide-angle X-ray scattering (GIWAXS). As a result, a champion power conversion efficiency (PCE) of 26.94% (certified as 26.66%, a very high certification efficiency of n-i-p structured perovskite devices) is achieved for the laboratory area (aperture area of the mask is 0.0618 cm 2 ). Moreover, a micro module device with an aperture area of 21.54 cm 2 was successfully manufactured and achieved a PCE of 24.60% (certified as 24.02%).