Department of Materials Science and Engineering, Massachusetts Institute of Technology , Cambridge, Massachusetts 02139, United States.
Department of Chemistry, Massachusetts Institute of Technology , Cambridge, Massachusetts 02139, United States.
ACS Appl Mater Interfaces. 2016 Apr 6;8(13):8511-9. doi: 10.1021/acsami.6b00635. Epub 2016 Mar 22.
Various electron and hole transport layers have been used to develop high-efficiency perovskite solar cells. To achieve low-temperature solution processing of perovskite solar cells, organic n-type materials are employed to replace the metal oxide electron transport layer (ETL). Although PCBM (phenyl-C61-butyric acid methyl ester) has been widely used for this application, its morphological instability in films (i.e., aggregation) is detrimental. Herein, we demonstrate the synthesis of a new fullerene derivative (isobenzofulvene-C60-epoxide, IBF-Ep) that serves as an electron transporting material for methylammonium mixed lead halide-based perovskite (CH3NH3PbI(3-x)Cl(x)) solar cells, both in the normal and inverted device configurations. We demonstrate that IBF-Ep has superior morphological stability compared to the conventional acceptor, PCBM. IBF-Ep provides higher photovoltaic device performance as compared to PCBM (6.9% vs 2.5% in the normal and 9.0% vs 5.3% in the inverted device configuration). Moreover, IBF-Ep devices show superior tolerance to high humidity (90%) in air. By reaching power conversion efficiencies up to 9.0% for the inverted devices with IBF-Ep as the ETL, we demonstrate the potential of this new material as an alternative to metal oxides for perovskite solar cells processed in air.
已经使用了各种电子和空穴传输层来开发高效的钙钛矿太阳能电池。为了实现钙钛矿太阳能电池的低温溶液处理，采用有机 n 型材料来替代金属氧化物电子传输层（ETL）。虽然 PCBM（苯并[C]吡咯-61-丁酸甲酯）已被广泛用于该应用，但它在薄膜中的形态不稳定性（即聚集）是有害的。在此，我们展示了一种新型富勒烯衍生物（异苯并呋喃-C60-环氧化物，IBF-Ep）的合成，它可用作基于甲脒混合铅卤化物的钙钛矿（CH3NH3PbI(3-x)Cl(x)）太阳能电池的电子传输材料，无论是在正常还是倒置器件结构中。我们证明，与传统受体 PCBM 相比，IBF-Ep 具有更好的形态稳定性。与 PCBM 相比，IBF-Ep 提供了更高的光伏器件性能（在正常结构中为 6.9%对 2.5%，在倒置结构中为 9.0%对 5.3%）。此外，IBF-Ep 器件对高湿度（90%）空气具有更好的耐受性。通过使用 IBF-Ep 作为 ETL 实现倒置器件的功率转换效率高达 9.0%，我们证明了这种新材料作为金属氧化物替代物用于在空气中处理的钙钛矿太阳能电池的潜力。
