Progress and limitation of lead-free inorganic perovskites for solar cell application

Abstract

Perovskites are at the forefront of research into possible replacements for cumbersome and expensive silicon-based solar cells. Lead-based inorganic and organic-inorganic hybrid perovskite solar cells have been breaking records for efficiency, approaching 25.7% in recent years. However, these suffer from stability problems and possible health hazards in the long term. Hence, there has been a parallel search for lead-free and preferably inorganic perovskite solar cells to match and ultimately exceed the achievements of lead perovskite analogs. This review examined a spectrum of the inorganic perovskite's chemical, optical, and physical properties for solar cell applications. Past research on lead-free perovskite has yielded lower efficiency due to structural instabilities primarily due to the site features of A and B. The type of dopants, concentration of dopants, and site-doping techniques all play a significant role in their efficiency and stability. Also, it was observed that the type and concentration of additives also have significant roles in their efficiency and stability. Another main challenge was chemical selections to determine single or double perovskite solar cell as sizes of the ‘A’ and ‘B’ site influences compound structural stabilities. Through literature, it was discovered that Cs2AgBiBr6 is the most prominent perovskite used in lead-free perovskite solar cells. This research recommends that instead of reinventing the wheel of seeking new perovskite, more experimental work needs to be done on the Cs2AgBiBr6 compound.