Application Of Heteroanthracene And Copper Phthalocyanine Hole Transport Material In Perovskite Solar Cells

As a crucial functional part of perovskite solar cell?PSC?,hole transport material?HTM?plays important role in hole extraction and transport,leading to high power conversion efficiency?PCE?.To date,2,2',7,7'-Tetrakis-?N,N-di-4-methoxyphenylamino?-9,9'-spirobifluorene?Spiro-OMeTAD?is admittedly the most recognized small organic molecule HTM.However,due to the complicated synthetic routes and the purification process,the cost is prohibitively high,limiting its large-scale application in future commercialization.Hence,the design and synthesis of novel low-cost and highly efficient HTMs is ungently desired for PSC.In this thesis,a series of phenoxazine?POZ?and phenothiazine dioxide?PDO?core building block based HTMs,and one copper phthalocyanines type HTM are reported.The influence of molecular configuration on material physical-chemical properities,hole mobility and conductivity,and photovoltaic performance are symtemacially studied.The mainly studies of this paper is the application of noval organic small molecule HTMs in PSCs.The traditional HTM Spiro-OMeTAD has problems such as complicated synthetic routes and synthesis cost prohibitively high.The detailed contents are listed below:1.Two novel simple-constructed and low-cost HTMs POZ9 and POZ10,incorporating a POZ core unit,were designed and synthesized for application in PSC.The typically semblable molecular structure of POZ9 and POZ10 cause them to possess similar energy levels.However,because of the small variations of N-substitution on POZ ring,the PSCs based on POZ10,achieved a PCE of 19.4%,while the PSC adopting POZ9 as HTM obtained a lower PCE of 17.1%.Moreover,the light intensity dependence research showed that POZ10 has a better hole transporting ability and can efficiently resist the charge recombination.2.Two novel PDO core building block-based HTMs,termed PDO1 and PDO2,were designed and synthesized.The introduction of a sulfuryl group in a core unit can deeply influence the energy levels and charge carrier mobilities of relative HTMs.The combined suitable energy level alignment,higher hole mobility and conductivity,as well as highly efficient hole transfer of PDO2 enable the PSC to achieve an impressive PCE of 20.2%and good stability when aged under ambient conditions.These results demonstrate the potential versatility of the PDO building block for further development of cost-effective and highly efficient HTMs for PSCs.3.A methoxy substituted copper?II?phthalocyanine CuPc-?OMe?₈ was synthesized and successfully applied as dopant-free HTM in the PSCs.The optimized PSC devices based on the dopant-free CuPc-?OMe?₈ achieve the highest efficiency of18.3%,which is competitive with traditional doped Spiro-OMeTAD.More importantly,an impressively superior long-term stability is represented by dopant-free CuPc-?OMe?₈ based device.These results highlight that CuPc-?OMe?₈ is a promising dopant-free HTM for application in PSCs.