High efficient organic ultraviolet photovoltaic devices based on gallium complex

High efficient organic ultraviolet (UV) photovoltaic devices comprising 4,4′,4″-tri-(2-methylphenyl phenylamino) triphenylamine (m-MTDATA) and tris-(8-hydroxyquinoline) gallium (Gaq3) as the electron donor and acceptor, respectively, are demonstrated. The m-MTDATA/Gaq3 bilayer device shows a short-circuit current density of 59.3 μA/cm2, a open-circuit voltage of 1.85 V, a fill factor of 0.41, and a power conversion efficiency of 3.74% under illumination of a 1.2 mW/cm2 365 nm UV light. And this power conversion efficiency is superior than that of the device based on tris-(8-hydroxyquinoline) aluminum with the same device structure, which is attributed to the high electron mobility of Gaq3 and the low exciton loss via radiation decay and hence more exciton dissociation in m-MTDATA/Gaq3 device.