Hierarchically Structured Hole Transport Layers of Spiro-OMeTAD and Multiwalled Carbon Nanotubes for Perovskite Solar Cells

作者：Lee Jiyong; Menamparambath Mini Mol; Hwang Jae Yeol; Baik Seunghyun^*

来源：Chemsuschem, 2015, 8(14): 2358-2362.

DOI：10.1002/cssc.201403462

• hierarchical structure
• hole transport layer
• multi-walled carbon nanotubes
• perovskite solar cells
• spiro-ometad

The low electrical conductivity of spiro-OMeTAD hole transport layers impedes further enhancements of the power conversion efficiency (PCE) of perovskite solar cells. We embedded multiwalled carbon nanotubes (MWNTs) in spiro-OMeTAD (spiro-OMeTAD/MWNTs) to increase carrier mobility and conductivity. However, direct electrical contact between CH3NH3PbI3 and the MWNTs created pathways for undesirable back-electron transfer, owing to the large work function of MWNTs, limiting enhancements of the PCE. A hierarchical structure of pure spiro-OMeTAD and spiro-OMeTAD/MWNTs was designed to block back-electron transfer and fully exploit the enhanced charge transport of spiro-OMeTAD/MWNTs. The enhanced fill factor, short-circuit current density, open-circuit voltage, and PCE (15.1%) were achieved by using this hierarchical hole transport layer structure (MWNT concentration=2wt%). The perovskite solar cells were fabricated by a low-temperature solution process, further decreasing their per-Watt cost.

• 出版日期2015-7-20