Eliminating interface charge accumulation and inhibiting ion migration are useful for improving the performance of 2,2',7,7'-tetrakis(N,N-di-p-methoxyphenyl-amine)-9,9'-spirobifluorene (spiro- OMeTAD) perovskite solar cells (PVSC) efficiency and operational stability remain a challenge. Chen Yiwang, Tan Licheng and others from Nanchang University reported a new type of interface engineering. The self-assembled eutectic layer (SAM-CL) for PVSC is composed of 1-pyrrolemethylamine hydrochloride (PRMA) on the surface of perovskite. Monolayer and 2,3,5,6-tetrafluoro-7,7',8,8'-tetracyanoquinolinedimethyl doped in spiro-OMeTAD via intermolecular π-π interactions and hydrogen bonds constructed from base ketone (F4TCNQ).
SAM-CL optimizes the interface energy level arrangement through the charge transfer effect, thereby eliminating interface charge accumulation. In addition, the excellent blocking effect of the large pyrene ring and fluorine atoms in SAM-CL hinders ion migration and moisture intrusion, thereby significantly improving the stability of PVSC.
The resulting PVSC has a power conversion efficiency (PCE) of 24.03% at a high open circuit voltage of 1.21V and excellent stability. Without encapsulation, the PVSC operates continuously in air with a relative humidity of 70-80%. After 1800 hours of operation, 85% of the initial PCE can still be maintained.
Xueying Wang et.al Elimination of Charge Accumulation by Self-assembled Cocrystal Interlayer for Efficient and Stable Perovskite Solar Cells EES 2023
DOI: 10.1039/D3EE03550F