Planar Perovskite Solar Cells Using Perovskite CsPbI3 Quantum Dots as Efficient Hole Transporting Layers

Abstract

Perovskite CsPbI3 quantum dots (QDs) were synthesized as a hole-transporting layer (HTL) of a planar perovskite solar cell (PSC). By using the Octam solution during the ligand engineering, CsPbI3 QDs exhibits a denser grain and a larger grain size due to the short-chain ligands of Octam. In addition, CsPbI3 QDs with the Octam solution showed a smooth and uniform surface on MAPbI3 film, indicating the QDs improved the microstructure of the MAPbI3 perovskite film. As a result, the PSC with CsPbI3 QDs as an HTL has the optimal open-circuit voltage as 1.09 V, the short-circuit current as 20.5 mA/cm2, and the fill factor (FF) as 75.7%, and the power conversion efficiency (PCE) as 17.0%. Hence, it is inferred that introducing QDs as a HTL via the ligand engineering can effectively improve the device performance of the PSC.

Nanocrystals as performance-boosting materials for solar cells

“…67–69 Besides NiO, some other metal oxide NCs such as MoO 2 , 70 Co 3 O 4 , 71 Cu 2 O, 72 CuCrO 2 , 73 CuGaO 2 , 74 and CsPbI 3 (ref. 75) have been used as efficient top HTL for PSCs due to their excellent properties. It can be noticed that when PbS NCs are used as top HTL in solar cells, the light harvesting layers are mostly based on the PbS/Se family.…”

“…11,14,15,17–22 Additionally, perovskite NCs are also good alternatives for light harvesting in solar cells. 12–14,16,23–28 Besides active layers (light harvesting layers), functional layers based on NCs, mainly including hole transport layers (HTLs), 29–99 electron transport layers (ETLs) 100–173 and interfacial functional layers (IFLs), 174–221 are of great importance in solar cells. Notably, NC additives also boost the performance of solar cells through defect passivation, plasmonic effect, solar concentration, light up-conversion and down-conversion/shifting, light scattering and reflection, and heat sinks.…”