In an effort to diminish the cost of perovskite solar cells (PSCs) with regard to hole transport materials (HTMs), we employed an easily attainable condensation route to synthesize a cheap and efficient HTM. Using a newly engineered small organic molecule, N,N0-(naphthalene-1,5-diyl)bis(1-(2,3- diphenylquinoxalin-6-yl)-1-phenylmethanimine), coded as BEDN, the power conversion efficiency (PCE) reached 17.85%, comparable to that of the state-of-the-art HTM spiro-OMeTAD (19.50%). The BEDN's estimated cost is 1.38 ($ per g), which is considerably cheaper than spiro-OMeTAD, 92 ($ per g). The low cost and high efficiency are promising in commercialization of perovskite solar cells.
