Interfacial <i>versus</i> Bulk Properties of Hole-Transporting Materials for Perovskite Solar Cells: Isomeric Triphenylamine-Based Enamines <i>versus</i> Spiro-OMeTAD
Ju̅ratė Simokaitienė, Monika Cekaviciute, Kristina Baucyte, Dmytro Volyniuk, Ranush Durgaryan, Desiré Molina, Bowen Yang, Jiajia Suo, YeonJu Kim, Demétrio A. da Silva Filho, Anders Hagfeldt, Gjergji Sini, Juozas V. Gražulevičius
Abstract
/V·s, which are higher than those in spiro-OMeTAD at the same electric fields. DFT-based analysis points to the presence of several conformers close in energy at room temperature. The newly synthesized hole-transporting materials (HTMs) were used in perovskite solar cells and exhibited performances comparable to that of spiro-OMeTAD. The device containing one newly synthesized hole-transporting enamine was characterized by a power conversion efficiency of 18.4%. Our analysis indicates that the perovskite-HTM interface dominates the properties of perovskite solar cells. PL measurements indicate smaller efficiency for perovskite-to-new HTM hole transfer as compared to spiro-OMeTAD. Nevertheless, the comparable power conversion efficiencies and simple synthesis of the new compounds make them attractive candidates for utilization in perovskite solar cells.