Preparation,Characterization And Photovoltaic Applications Of Tungsten-oxide-based Hole Transport Materials

Polymer solar cells(PSCs)and perovskite solar cells(Pe SCs)have been regarded as great promising solar cells due to their great potential in terms of light weight,low-cost and easy fabrication on large area flexible substrates.With the continuous efforts from global scientists,the power conversion efficiency(PCE)of PSCs and Pe SCs reached 11.5% and 22.7%,respectively.The hole transport layer(HTL)of PSCs or Pe SCs is an important component of the photovoltaic devices.HTL can optimize the ITO film,enhance interfacial charge transfer,and reduce charge recombination.Here,we report a new material that Poly(3,4-ethylenedioxythiophene)coated tungsten oxide nanorods(WOX@PEDOT).The average PCE of WOX@PEDOT based devices reached 12.89%,which is comparable to that of PEDOT:PSS based devices.In order to improve the performance of perovskite solar cell,we doped WOX@PEDOT nanorods in PEDOT:PSS,and the doped PEDOT:PSS based devices with an average PCE of 14.30%,suggesting that WOX@PEDOT is an efficient HTL to achieve low-cost and high perofrmance perovskite solar cells.We also successfully developed tungsten oxide thin film with low temperature solution method,which is rich in oxygen vacancies(WOX),mainly using hydroquinone as an antioxidant to inhibit the complete oxidation of tungsten oxide precursor solution during annealing process.The PCE of PSCs(with P3HT:PC61BM as the active layer)based on WOX as HTL achieved 3.68%,which is equivalent to that of PEDOT:PSS based PSCs.WOx films are very encouraging and expected to be a new way to enhance the photovoltaic performance of PSCs.