6.5% efficient perovskite quantum-dot-sensitized solar cell

Abstract

Highly efficient quantum-dot-sensitized solar cell is fabricated using ca. 2–3 nm sized perovskite (CH₃NH₃)PbI₃ nanocrystal. Spin-coating of the equimolar mixture of CH₃NH₃I and PbI₂ in γ-butyrolactone solution (perovskite precursor solution) leads to (CH₃NH₃)PbI₃ quantum dots (QDs) on nanocrystalline TiO₂ surface. By electrochemical junction with iodide/iodine based redox electrolyte, perovskite QD-sensitized 3.6 μm-thick TiO₂ film shows maximum external quantum efficiency (EQE) of 78.6% at 530 nm and solar-to-electrical conversion efficiency of 6.54% at AM 1.5G 1 sun intensity (100 mW cm⁻²), which is by far the highest efficiency among the reported inorganic quantum dot sensitizers.