Study On Electron Transfer Efficiency Of Photoelectric Functional Material Based On Fullerene

The interest in organic solar cells has risen strongly of late years,due to their interesting properties in terms of the prospect of high throughput and low-cost processing,and many organic semiconductors exhibit very high absorption coefficients,making them promising compounds for photovoltaic devices.Besides,compared with silicon solar cells which dominate the market these days,for applications with widely raw and processed materials,low-cost,low toxicity and cheaper processing organic solar cells will be easier to realize,which make organic photovoltaics have already entered the market for niche products.Unfortunately,although organic solar cell has numerous advantages in terms of low-cost as well as high-energy,the relatively low photoelectric conversion efficiency restricts developing of organic solar cell to some extent.Increasing the photoelectric conversion efficiency of organic solar cell has become a topic of general interest in physics,chemistry,biology and material science.In this thesis,the theory of Marcus-Levich-Jortner was selected as study model.And excited-state dynamical information and infrared vibrational spectra of N-9``-heptadecanyl-2,7-carbazole-alt-5,5-(4`,7`-di-2-thienyl-2`,1`,3`-benzothiadiazol e)(PCDTBT):[6,6]-phenyl C70-butyric acid methyl ester(PC70BM)(PCDTBT: PC70BM)and N,N`-3,4,9,10-perylenediimide(PDIB):[6,6]-phenyl C70-butyric acid methyl ester(PC70BM)(PDIB: PC70BM)interface in different external electric fields were performed.In the first place,we theoretically investigated the vibrational quantum tunneling effect in controlling the rate of photoinduced electron transfer for BHJ solar cell.The photo active layer of PCDTBT: PC70 BM was selected as the model studied here,due to its excellent performance in PSCs.Also the external electric field influence was considered,which is another factor affecting the ET reaction rate in real solar cell devices.It is essential for the electron transfer reactions to take into account of vibrational excitation influence and perturbed nuclear-electronic interactions,due to analysis result.Then,the electron coupling VDA(Fext),gibbs free energyΔG(Fext),reorganization energiesλ(Fext),and carrier mobility of PDIB:PC70BM blends were theoretically simulated in different external electric field strengths,making sure the extent of impact on rate of photoinduced charge separation and charge recombination by these parameters.ibrational quantum tunneling effect was applied for PDIB:PC70BM blends.As a result,not only external electric field affected the rate of electron transfer,but vibrational quantum tunneling effect in controlling the rate of photoinduced electron transfer for BHJ solar cell.