dc.description.abstract | Perovskite solar cells (PSCs) have developed rapidly due to the simple assembly process and low raw material costs. The commonly used hole transporting material (HTM) with high-efficiency PSCs is spiro-OMe-TAD, but its hole mobility is low. Therefore, the development of polymers with high hole mobility as the hole transporting materials (HTMs) is an important research. This study is to develop D-A polymeric HTMs for PSCs. P15, which is previously prepared in our laboratory, having BDT (benzodithiophene) derivative (with high planarity and rigid structure) as the donor unit and PQ (pyrido-quinoxaline) derivative (with good electron withdrawing ability) as the acceptor unit was used as a model polymer. Triethylene glucol monomethyl ether (TEG) unit was used as a substitute to increase the solubility to form polymer P19. Thiophene in P15 and P19 was replaced with selenophene as the π-bridge to obtain polymer P17 and P20. Chlorine atoms were introduced into the side chains of the donor (to increase the interaction between polymer chains) in P15, P17, and P20 to synthesize P16, P18, and P21. The thermal stability of the polymers are about 261 oC ~ 348 oC. The water contact angle of all polymer films is greater than 90o, which means they are all hydrophobic. UV-Vis absorption spectra show that the λmax of the six polymers falls between 608 and 654 nm, and the λmax values of P17, P18, P20, and P21, which has selenophene bridge are longer than those of P15, P16, P19 where the π-bridge is thiophene. The HOMO energy levels of P16, P18, and P21 having chlorine atoms in the side chain are lower than those of P15, P17, P19, and P20 without chlorine atoms. PSC devices based on P17, P18, P20, and P21 (with π-bridge of selenophene) HTLs have higher efficiency than those of P16 and P19 (with thiophene π-bridg) as HTLs. However, the photoelectric efficiency of the PSC device assembled by the polymer P15 (15.56%) with HTL is higher than that of the device assembled by the P16, P17, and P18 as the HTL. Because the molecular weight of P15 is the largest, the film surface is the most flat and dense. The efficiencies of PSCs based on P19, P20, and P21 HTMs are very low. It is due to the three polymers cannot form a continuous film on top of perovskite by spin coating method. | en_US |