Experimental and numerical study of different metal contacts for perovskite solar cells

Various metal layers grown by e-beam evaporator have been studied to be used as metal contacts for scalable perovskite photovoltaic (PV) devices. The evaporated films consisting of gold (Au), silver (Ag), nickel (Ni), titanium (Ti), tin (Sn), copper (Cu), and molybdenum (Mo) were grown on glass substrates at room temperature with an optimized thickness. Later, the measured optical properties such as transmission and absorptance of such films were used computationally to extract the optimum device performance using SCAPS-1D software. Among all the layers, Ti-based perovskite solar cells outperform other metal contacts with a power conversion efficiency of (>27%). The films were characterized optically, topologically, structurally, and morphologically using ultraviolet—visible (UV—Vis) spectrometry, atomic force microscopy, x-ray photoelectron spectroscopy (XPS), three-dimensional (3D) profilometry, and scanning electron microscopy. The morphological data confirm the growth of compact, uniform, and defect-free metal films as confirmed by the field emission scanning electron microscopy. Contact angle measurement was also performed to determine the wettability of metal surfaces. Both Au and Ni films were found semi-hydrophilic which shows the adaptability of better stability through repelling water from the surface. The computational analysis confirms that screening of suitable metal back contact is necessary to increase device performance and stability significantly.