Enriching solar-cell front electrodes with AgMgO nanoparticles via physical deposition: A morphological and optical investigation

Core-shell metal-oxide nanoparticles (NPs) have been extensively exploited in Perovskite solar cells (PSCs) to improve light harvesting and power conversion efficiency. Herein, we exploit a sequential physical method based on nanocluster magnetron-sputtering techniques and MgO deposition to grow Ag NPs —embedded in an ultrathin MgO matrix— on top of a multilayered substrate, which acts as a front electrode in PSCs. The overall system morphology is investigated by Scanning Electron Microscopy (SEM) for different Ag@MgO coverages. The optical reflectance (R) and transmittance (T) spectra of both pristine and functionalized multilayer substrates are acquired for different substrate batches, showing remarkable differences. Data are analyzed by a specifically designed fitting procedure, which evaluates the contribution to R and T of each layer and extracts their complex refractive index ñ, as well as their morphological properties, i.e. their thickness and roughness.