| 초록 |
Conventional perovskite solar cells (PSCs) have used 2,2′,7,7′-tetrakis(N,N′-di-p-methoxyphenylamine)-9,9′-spirobifluorene (spiro-OMeTAD) as hole transporting materials (HTMs). However, this material causes problems such as reproducibility and stability. To alleviate these issues, we introduced a tungsten oxide (WO3)@Spiro-OMeTAD double-layered HTM. The best efficiency of 21.44% was demonstrated using a WO3@Spiro-OMeTAD in planar PSCs. We investigated the electronic properties of new HTMs by some spectroscopy measurements (e.g., space-charge–limited current, photoluminescence and electrochemical impedance). The resultant device exhibited the high open-circuit voltage (VOC) of 1.17 V owing to lowered the quasi-Fermi energy level and reduced charge recombination. We aged PSCs with the WO3@Spiro-OMeTAD HTM under thermal and humid conditions and the devices well maintained the initial efficiency. |
