4-Tert-butylpyridine Free Organic Hole Transporting Materials for Stable and Efficient Planar Perovskite Solar Cells
Journal
Advanced Energy Materials
Journal Volume
7
Journal Issue
19
Date Issued
2017
Author(s)
Abstract
Abstract 4‐ Tert ‐butylpyridine ( t BP) is an important additive in triarylamine‐based organic hole‐transporting materials (HTMs) for improving the efficiency and steady‐state performance of perovskite solar cells (PVSCs). However, the low boiling point of t BP (196 °C) significantly affects the long‐term stability and device performance of PVSCs. Herein, the design and synthesis of a series of covalently linked Spiro[fluorene‐9,9′‐xanthene] (SFX)‐based organic HTMs and pyridine derivatives to realize efficient and stable planar PVSCs are reported. One of the tailored HTMs, N2,N2,N7,N7‐tetrakis(4‐methoxyphenyl)‐3′,6′‐bis(pyridin‐4‐ylmethoxy) spiro[fluorene‐9,9′‐xanthene]‐2,7‐diamine ( XPP ) with two para‐position substituted pyridines that immobilized on the SFX core unit shows a high power conversion efficiency (PCE) of 17.2% in planar CH 3 NH 3 PbI 3 ‐based PVSCs under 100 mW cm −2 AM 1.5G solar illumination, which is much higher than the efficiency of 5.5% that using the well‐known 2,2′,7,7′‐tetrakis‐( N , N ‐di‐ p ‐methoxy‐phenyl‐amine)9,9′‐spirobifluorene (Spiro‐OMeTAD) as HTM (without t BP) under the same condition. Most importantly, the pyridine‐functionalized HTM‐based PVSCs without t BP as additive show much better long‐term stability than that of the state‐of‐the‐art HTM Spiro‐OMeTAD‐based solar cells that containing t BP as additive. This is the first case that the t BP‐free HTMs are demonstrated in PVSCs with high PCEs and good stability. It paves the way to develop highly efficient and stable t BP‐free HTMs for PVSCs toward commercial applications.
SDGs
Publisher
Wiley-VCH Verlag
Type
journal article