Successive surface engineering of TiO2 compact layers via dual modification of fullerene derivatives affording hysteresis-suppressed high-performance perovskite solar cells
| Autor: | Jieming Zhen, Weiran Zhou, Zhimin Fang, Qing Liu, Shangfeng Yang, Dan Li, Pengcheng Zhou, Tao Chen |
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| Rok vydání: | 2017 |
| Předmět: |
Materials science
Passivation Renewable Energy Sustainability and the Environment Energy conversion efficiency Heterojunction Nanotechnology 02 engineering and technology General Chemistry Surface engineering 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences 0104 chemical sciences Chemical engineering Surface modification General Materials Science Charge carrier Wetting 0210 nano-technology Perovskite (structure) |
| Zdroj: | Journal of Materials Chemistry A. 5:1724-1733 |
| ISSN: | 2050-7496 2050-7488 |
| Popis: | Interfacial engineering is critical for highly efficient charge carrier transport in perovskite solar cells (PSCs). Herein, we developed a new method, called successive surface engineering, that affords PSCs with enhanced efficiency and dramatically suppressed current–voltage hysteresis. Upon modifying the TiO2 compact layer, which is commonly used as an electron transport layer (ETL) in regular-structure (n–i–p) planar heterojunction (PHJ) PSCs, by successively incorporating [6,6]-phenyl-C61-butyric acid methyl ester (PC61BM) and an ethanolamine (ETA)-functionalized fullerene (C60-ETA) synthesized facilely via a one-pot nucleophilic addition reaction, the average power conversion efficiency (PCE) of the CH3NH3PbI3-based PHJ-PSC devices increased from 13.00% to 16.31%; the best PCE attained was 18.49%, which, to our knowledge, represents the highest PCE reported to date for regular-structure PHJ-PSCs devices based on fullerene-modified TiO2 interlayers. In contrast, single surface engineering of the TiO2 layer with a PC61BM or C60-ETA layer alone results in only negligible changes in PCE, revealing the synergistic effect of these two fullerene derivatives: the PC61BM layer can passivate the traps on the TiO2 surface, while the subsequent C60-ETA layer not only improves the wettability of the perovskite film on the ETL but also facilitates electron transport across the interface between the perovskite and the TiO2 ETL. The structural and morphological characterizations show that following dual surface modification of the TiO2 layer with PC61BM and C60-ETA, both the surface coverage and crystallinity of the CH3NH3PbI3 perovskite film are improved. Steady-state photoluminescence decay and electrochemical impedance spectroscopic studies manifest that the dual surface modification substantially improves the charge extraction efficiency and suppresses charge recombination. As a consequence, this dual surface modification leads to an obvious increase of the short-circuit current density (Jsc), which contributes primarily to the PCE enhancement. Additionally, because PC61BM may induce passivation of the traps on the TiO2 surface and in the perovskite layer, remarkably, the hysteresis of the current–voltage response is dramatically suppressed following the dual surface modification. |
| Databáze: | OpenAIRE |
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