Keywords
Abstract
Two new compounds BT-PDI and BT2-PDI2 were synthesized by the Sonogashira reaction between 4,7-diethynyl-2,1,3- benzothiadiazole and bromoperylene diimide derivatives. The HOMO and LUMO energy levels estimated by UV-VIS spectroscopy and cyclic voltammetry were -5.66/-3.75 and -5.33/-3.41 eV for the BT-PDI and BT2-PDI2, respectively; both compounds form high-quality and smooth coatings on the perovskite surface with the root mean square roughness values 5.95 and 7.80 nm for the BT-PDI and BT2-PDI2 films, respectively; the electron mobilities in the solid films estimated by photo-CELIV method are equal to 5.0 × 10-5 and 3.0 × 10-5 cm2 V-1 s-1, respectively. Both compounds being tested as electron transport layers in perovskite solar cells showed efficiency values of 14.44 and 13.01% for BT-PDI and BT2-PDI2, respectively.