Current Status of High-Efficiency Solar Cells 1

The performance of the best-certified organic–inorganic halide perovskite solar cells has improved by more than 150% relative and 8% absolute (Figure 3.1) over the last few years making it the fastest advancing photovoltaic technology. ¹ There has been a move from the widely researched CH₃NH₃PbI₃ (MAPbI₃) ^1–2 toward mixed perovskites by incorporating HC(NH₂)₂ ⁺ (FA⁺) to take advantage of lower bandgap and therefore higher current but is often compromised by the addition of Br⁻ ions for better perovskite phase stability. ³ The addition of Cs ⁴ and most recently Rb ^5,6 also produce cells with excellent efficiencies (although not certified) and stability.