A Theoretical Study Of Key Parameters Of Dye-sensitized Solar Cells And The Design Of New Organic Dyes

Device parameters of dye-sensitized solar cells（DSC）,such as the short-circuit current density(J_SC),open-circuit voltage（Voc）and power conversion efficiency（PCE）,offer important diagnostics for assessing the properties of a given DSC.However,no unified and effective calculation model has been reported up to now,although these parameters can be easily obtained experimentally.Worse still,the effective theoretical guidance in the development of DSC and the property improvement are hardly further accomplished because of the above reason.A computational method that predicts these DSC device parameters would therefore be very valuable to offset these experimental reproducibility issues in DSC device physics.This paper first proposes a new calculation method（model）from the perspective of energy level correction.The new model abandons the inaccurate time parameters and empirical parameters used in the traditional model,which guarantees its accuracy and applicability from the mechanism.Then,a variety of classical DSC sensitized by L0,L1,L2,WS-2,WS-92,or C281 were selected and the density functional theory was employed to test the accuracy and applicability of the new model.Comparing the results with experimental measurements of DSC device parameters,the maximum deviations in J_SC,V_OC and PCE across all of these six case studies of DSC are 1.85 mA·cm^-2,74.4 mV,and0.36%,respectively,with the maximum percentage deviation of PCE being 4.2%.It can be seen that the theoretical experimental errors is greatly reduced and the new model is a reliable research tool for DSC photovoltaic performance.To quickly evaluate the performance of a DSC,we have further developed a model calculation implementation software that greatly facilitates the use of the new model.Finally,based on the previous study,a batch of new dyes are designed using the classic C286 as a prototype.After layer screening,the new model is used to evaluate device parameters of the remaining DSC.The results show that the DSC sensitized with the new dye CH3 will have more excellent photovoltaic performance.Briefly,this paper has provided a new instructive theoretical model and a practical tool for the research of DSC photovoltaic performance and the design and screening of new DSC dyes.