The manufacturing procedure of perovskite film deposited by the solid-liquid two-step method is shown in Fig. S11, and the target perovskite film prepared by the solid-liquid two-step method exhibited more uniformity compared with blade-coating perovskite film (Fig. S12). PSMs with the device structure of FTO/NiO
x/perovskite/C
60/BCP/Cu were fabricated (
Fig. 5a), and the photographs and structure of the PSMs we prepared are also shown in
Figs. 5b and S13. The width of each sub-cell in the PSMs is 0.733 cm, and the dead width for connecting sub-cells is 0.033 cm. Therefore, the GFF (geometric fill factor), the ratio of the active area (61.56 cm
2) to the aperture area (64.48 cm
2), is 95.47%. Their
J-V curves are plotted in Fig. S14, and the parameters are summarized in
Table 1. The pristine PSMs based on the solid-liquid two-step method show a PCE of 15.81%, which was higher than that of the blade-coated device (13.47%) due to the better crystallinity. The PSM based on PVSK/CsBr exhibited a PCE of 17.43% with enhanced
VOC (11.25 V) and
FF (78.39%), which is attributed to the modification of NiO
x and higher-quality perovskite film. As shown in
Fig. 5c, after the coordinated regulation of the perovskite buried interface and crystal growth by CsBr and Urea, the corresponding device performance was significantly improved. The PSMs based on PVSK/CsBr + Urea achieved a PCE of 20.56% with a
JSC of 2.11 mA cm
−2,
VOC of 12.05 V, and
FF of 80.87% with an active area of 61.56 cm
2, which is the best performance for the
p-i-n type PSMs with active area > 40 cm
2 reported in the literature (
Fig. 5d and Table S3). The preferable crystal growth orientation and enlarged grain size were conducive to charge transporting, which were responsible for the increased
JSC. The significantly enhanced
VOC and
FF of the device based on CsBr + Urea were mainly attributed to the superior energy level alignment and suppressed defects in the perovskite layer. The integrated
JSC derived from EQE spectra were 1.80, 1.94, and 2.07 mA cm
−2 for the vapor-deposited PVSK, PVSK/CsBr, and PVSK/CsBr + Urea device, respectively (Fig. S15), which were close to their measured
JSC. In addition, the PSMs based on PVSK/CsBr and PVSK/CsBr + Urea exhibited good repeatability with a PCE
average of 19.53% and 16.57%, respectively (
Figs. 5e and S16), much better than that of pristine PVSK (PCE
average = 14.97%).