1. (a) Schematic illustration and (b) work function of the device, cross-sectional SEM images of C-PSCs: (c) device A, (d) device B and (e) device C, and (f) element distribution in the direction of the white arrow in (e)

2. Photographs of NiO_x dispersions for (left) spin-coating (SC), for (right) screen-printing (SP) (a) before and (b) after standing for 30 min

3. SEM images of (a) ZrO₂ mesoporous film, (b) spin- coated and (c) screen-printed NiO_x films, and (d) PL spectra for sample A (ZrO₂/MAPbI₃), sample B (ZrO₂/NiO_x (spin-coated)/ MAPbI₃), and sample C (ZrO₂/NiO_x(screen-printed)/MAPbI₃)

4. (a) XRD patterns of MAPbI₃ in different devices and (b) local magnified XRD patterns in range of 13.6°-14.6°

5. (a-c) J-V curves and (d) incident photon-to-electron conversion efficiency (IPCE) spectra and the integrated current density curves of different devices(a) Forward and reverse scans of device A, B and C; (b) Different thicknesses of NiO_x layer; (c) The optimum cells of device A and device C; Colorful figures are available on website

6. (a) J-V curves under dark conditions, (b) light-intensity dependence of V_OC (solid line: linear fitting), (c) transient photovoltage (TPV) decay curves, (d) transient photocurrent (TPC) decay curves, (e) Nyquist plots measured in the dark, and (f) Mott-Schottky plots for device A and device C; Colorful figures are available on website

7. Long-term storage stability of PSCs in air with relative humidity of 30%-40%(a) J_SC; (b) V_OC; (c) FF; (d) PCE

S1. XRD pattern of NiO_x nanoparticles prepared by chemical precipitation method

S2. Low magnification cross-sectional SEM images of (a) device B and (b) device C

S3. High magnification top-view SEM images of screen- printed (a) ZrO₂ and (b) NiO_x films

S4. Certified efficiency measurement report of device C