Acceptor-donor-acceptor type planar hole-transporting materials for efficient dopant-free perovskite solar cells

ABSTRACT

Acceptor-donor-acceptor (A-D-A) type organic small molecule (SM-1) has been explored as an efficient dopant-free hole transporting material (HTM) to replace spiro-OMeTAD in the perovskite solar cells. High quality smooth, uniform, and hydrophobic SM-1 HTM can be readily deposited through solution casting without any external dopants. The highly compatible highest occupied molecular orbital level of −5.15 eV of SM-1 with respect to the perovskite valence band, along with intrinsically rich hole conductive nature effectively extracts holes from perovskite and thereby showed a reasonably high power conversion efficiency of 10.54%. Henceforth, the SM-1 based PSCs results successfully demonstrate the advancement of dopant-free PSCs through design engineering of planar A-D-A type conjugated small molecules.

KEYWORDS:

• Acceptor-donor-acceptor small molecule
• dopant-free
• hole transporting material
• perovskite solar cells

Additional information

Funding

This work was supported by the National Research Foundation (NRF-2016R1E1A1A01942593) by the Ministry of Science, ICT of Korea. This research was also supported by the Dong-A University Research Fund.