1：Experimental Design and Method Selection:

A series of REs (Ce, Nd, Eu, Tb, and Yb) doped NiOx HTLs were prepared by a simple solution process for efficient inverted PSCs building. The influence of REs doping types and concentrations on the structural, electrical, and photoelectric characteristics of the NiOx HTL was systematically investigated.

2：Sample Selection and Data Sources:

The samples were prepared using nickel acetate tetrahydrate and rare earth nitrate hexahydrates with different molar ratios (1%, 3%, 5%) mixed into the solution with nickel acetate tetrahydrate and ethanolamine.

3：List of Experimental Equipment and Materials:

Materials included lead (II) iodide, methylammonium iodide, [6,6]-Phenyl-C61-butyric Acid Methyl Ester (PCBM [60]), nickel acetate tetrahydrate, and rare earth salts. Equipment included a solar simulator for J-V measurements, UV–Vis spectroscopy, X-ray diffraction spectra (XRD), scanning electron microscope (SEM), atomic force microscope (AFM), and X-ray photoelectron spectroscopy (XPS).

4：Experimental Procedures and Operational Workflow:

The HTLs were obtained by spin-coating the prepared NiOx or RE:NiOx precursor solutions on cleaned FTO substrates, followed by an annealing procedure. The MAPbI3 perovskite precursor was prepared via one-step method and coated onto the HTLs, followed by deposition of PCBM [60] solution and Ag layer via vacuum evaporation.

5：Data Analysis Methods:

The conductivity was calculated from J-V curves. The carrier concentration and mobility were obtained from Hall test. The work functions were measured by ultraviolet photoelectron spectroscopy (UPS). The photovoltaic parameters were obtained by measuring 20 devices.