Commentary article in Nature, Vol. 544, Issue. 7649, pp. 155-156, “Make perovskite solar cells stable”
Summary of article: Since its inception, perovskite solar cells have achieved quantum leaps in light conversion efficiencies from 2.2% in 2006 to 22.1% in 2016; however, their durability remains significantly less than those of conventional silicon solar photovoltaics. Hence, multiple ways have been put forward for improving the stability of these promising solar cells which can be degraded by exposure to moisture. For example, silicon solar cells could last for about 25 years under moisture and strong sunlight insolation, but perovskite solar cells could only last for months outdoors. One method for improving the durability of perovskite solar cells lies in altering their chemical composition. Perovskite solar cells have the chemical formula, ABX3, where A is a cation of organic or inorganic origin, B is a metal atom, and X is a halide. The first thought that came to my mind is: why halide? Isn’t bromide too reactive and thus unable to keep the crystal structure stable? As I am a novice, I do not have answers to this question.
I was wondering if keeping X constant as chloride would help improve the stability of perovskite compared to bromide, iodide or germanium. One potential problem with the use of chloride would be introduction of crystal imperfections resulting from the large ionic radius of chloride ion. X-ray photoelectron spectroscopy (XPS) would yield insights on the atomic composition of doping of ions in perovskite, while transmission electron microscopy (TEM) and powdered X-ray diffraction would tell a story of how chloride influences the subsequent doping of perovskite, and the structure of the resulting crystal.
Link to original article: https://www.nature.com/news/make-perovskite-solar-cells-stable-1.21807
Category: Interesting scientific articles, chemistry, materials, materials engineering,
Tags: perovskite solar cells, photo conversion efficiency (PCE), halide, stability, durability, silicon solar cell, doping, crystal structures, imperfections, transmission electron microscope, X-ray diffraction, X-ray photoelectron spectroscopy,