Tunning interfacial interaction strategy by asymmetric configuration to construct self-assembly materials for efficient organic solar cells

Developing highly ordered self-assembled monolayer is very critical and challenging for realizing high-performance organic solar cells. Herein, we develop an asymmetric carbazole derived molecule 1Cl-PACz by the introduction of single Cl atom to modulate energy level alignment and induce densely assembly. 1Cl-PACz exhibits an improved molecular dipole moment, thus modulating the work function of indium tin oxide (ITO) electrodes to facilitate charge extraction. Moreover, 1Cl-PACz is proven to have strengthened π-π interaction observed in its single crystal, forming densely assembly on the substrates. Excitingly, a champion power conversion efficiency of 19.0 % can be obtained when 1Cl-PACz is evaluated as hole-extraction channel, among the highest values for the SAMs derived cells to date. This study opens new avenues for exploring high-performance SAMs materials to boost the performance of OSC devices.