RESUMO
A readily available small molecular hole-transporting material (HTM), OMe-TATPyr, was synthesized and tested in perovskite solar cells (PSCs). OMe-TATPyr is a two-dimensional π-conjugated molecule with a pyrene core and four phenyl-thiophene bridged triarylamine groups. It can be readily synthesized in gram scale with a low lab cost of around US$ 50 g-1 . The incorporation of the phenyl-thiophene units in OMe-TATPyr are beneficial for not only carrier transportation through improved charge delocalization and intermolecular stacking, but also potential trap passivation via Pb-S interaction as supported by depth-profiling XPS, photoluminescence, and electrochemical impedance analysis. As a result, an impressive best power conversion efficiency (PCE) of up to 20.6 % and an average PCE of 20.0 % with good stability has been achieved for mixed-cation PSCs with OMe-TATPyr with an area of 0.09â cm2 . A device with an area of 1.08â cm2 based on OMe-TATPyr demonstrates a PCE of 17.3 %.
RESUMO
A combined study of electrochemical measurements, intervalence charge transfer analysis, and DFT calculations suggests that the degree of urea-mediated electronic coupling between two cyclometalated ruthenium sites is enhanced by the coordination of urea with Br- or Cl-via hydrogen bonding. In contrast, the redox waves of the diruthenium complex become highly irreversible in the presence of relatively strong basic anions such as H2PO4-, F-, or OAc-. This work demonstrates that the anion-urea interaction can be employed to regulate the electronic coupling and electron transfer between redox-active sites, suggesting the potential applications of the urea-functionalized diruthenium complex in anion sensing and stimuli-responsive molecular electronics.
RESUMO
Two new hole transporting materials (HTMs) based on triphenylamine and carbazole core moieties are designed and applied in planar perovskite solar cells. 18.2% power conversion efficiency (PCE) has been achieved, and 84% of the initial performance can be retained after 50 days.