Ag, Au, Pt prove best metal-contacts for perovskite solar cells. Ag and Cu are chemically unstable. Ni and Cr show low performance.

No abstract

Solar cells with high efficiency, low cost, and high stability are the target for the new generation of solar cells. A fully printable perovskite (CHNHPbI) solar cell (PSC) with device architecture FTO/TiO/AlO/NiO/C is fabricated in the current research as a low-cost and relatively stable structure and is investigated to determine how different fabrication factors such as the thickness of the insulating spacer layer (AlO) or treatments such as heat and UV-O treatments can affect the interfacial properties of this multilayer mesoporous structure. X-ray photoelectron spectra (XPS) show that UV-O treatment increases the Ni(NiO) phase on the surface of the black nickel oxide layer leading to better charge extraction and increasing open-circuit voltage (V) up to 0.945 V. We observe improved CHNHPbI formation inside the mesoporous layers by the PbI penetration at a higher temperature. Impedance spectral together with current-voltage measurements show the effect of thickness for the insulator layer in the internal and interfacial resistances and photovoltaic characteristics of the cell. The best performance of the carbon-based PSC attains power conversion efficiency of 12.1% with the thickness of the AlO layer at 450 nm.

Perovskite solar cells are well known for being low cost, solution‐based, and efficient solar cells; however, the high price of the conventional hole‐collector electrode (Spiro‐OMeTAD/Gold) and the high price and complexity of depositing gold on large scales are major barriers against commercializing them. Herein, an effective carbon composite electrode is introduced for a low‐cost perovskite solar cell with CuIn0.75Ga0.25S2 hole transport material to solve this problem. The carbon electrode is deposited by the doctor blade method using a paste composed of flakes of graphite, carbon black, and a kind of hydrophobic polymer (polystyrene or poly‐methyl methacrylate). It is investigated how the weight ratio of carbon black to graphite and type of binder affect sheet resistance and resistivity of carbon composite layer. The effects of carbon electrode composition on the charge transport resistance at the CuIn0.75Ga0.25S2/perovskite interface are investigated using impedance spectroscopy in different light intensities of white light and light with different wavelengths of 530, 660, and 740 nm. The best efficiency of 15.9% is obtained for the champion cell (fabricated outside the glovebox), which is close to the best efficiency of the reference cell with conventional Spiro‐OMeTAD/Gold hole‐collector that is 16.3%.