A sequential condensation route as a versatile platform for low cost and efficient hole transport materials in perovskite solar cells

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,N′-(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.