Influence of metal salts (Al, Ca, and Mg) on the work function and hole extraction at carbon counter electrodes in perovskite solar cells

Carbon Electrodes for Perovskite Photovoltaics: Interfacial Properties, Meta‐analysis, and Prospects

“…[124][125][126][127] Moreover, Don et al showed that metal salts (e.g., aluminum nitrate nonahydrate, calcium chloride, and magnesium acetate tetrahydrate) can be ball-milled into a graphite and carbon black mixture to raise the work function of the resulting material. [128] Ultraviolet photoelectron spectroscopy (UPS) showed a systematic increase in the electrode work function for carbon samples modified with metal salts, specifically in the order: neat carbon (4.14 eV) < magnesium acetate-modified (4.28 eV) < calcium-chloride modified (4.32 eV) < aluminum nitrate-modified (4.59 eV) carbon. Planar HSL-free devices using aluminum nitrate-modified electrodes showed improved PCE (9.91%) compared to devices made with neat carbon electrodes (8.83%).…”

“…[202] Metallic additives and microscopic carbon structures (such as graphene and CNTs) have been demonstrated to improve the conductivity of carbon electrodes. [52,119,121,128,[145][146][147] Some studies have also reported the use of a metal foil top layer to improve the electrode conductivity. [58,118,203] In this regard, macroscopic carbon structures, such as carbon papers, felts, and cloths, are also well-suited to this application.…”