Application And Research On Device Performance Of Hybrid Interfacial Materials In Organic Solar Cells

Recently, many efforts have been focusing on the study of interface, which leading to the extendeddevelopment of novel interfacial materials. For conventional OSCs, thepoly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)(PEDOT:PSS) is used as anode interlayer, andlow work function metals (like Ca and Ba) are used as the cathode. However, both PEDOT:PSS and lowwork function metals are important degradation factors of the devices because of their erosive orair-sensitive properties. Novel interface modification materials and inverted OSCs have been extensivelyinvestigated and shown promising device performance. Interlayer materials including the inorganiccathode/anode materials and the organic cathode/anode materials are highlighted in device fabrication tooptimize the performance of OSCs.Organic interfacial materials are generally more hydrophobic than the inorganic. The contact betweeninterface and active layer should be commonly more intimate, while the organic interlayer will be easier tobe corroded by the solution. Moreover, the carrier mobility of organic materials is far less than that of theinorganic semiconductors. As analyzed above, the concept of hybrid interlayer material is advanced in thispaper, and the hybrid interfacial materials CdS/ZnS-P (BCP, Bphen, Mphen, Phen) are designed andsynthesized. As follows:1. Hybrid interlayer CdS-P (including CdS-BCP, CdS-Bphen, CdS-Mphen, CdS-Phen) has beenobtained by the way of in-situ growth. BCP and phenanthroline derivatives(Bphen, Mphen, Phen) wereused to modify CdS as electron transport interlayers in the inverted organic solar cells (OSCs). Deviceswith CdS-BCP as interlayer exhibited excellent stability, only14.2%decay of efficiencies was observedafter stored in glovebox for3264hours (136days) in comparison with reduction of45%to theconventional devices. For the optimized inverted solar cells incorporating the hybrid CdS-P (CdS-BCP,CdS-Bphen, CdS-Mphen, CdS-Phen) buffer layer, the PCEs are significantly improved from3.09%to8.36,7.84,6.69,6.57%respectively, compared with the pristine CdS interlayer.2. Phenanthroline analogues (BCP, Bphen, Mphen, Phen) were utilized to modify the ZnS as electrontransport interlayers in the inverted organic solar cells. Performances of the inverted solar cells areimproved enormously after the modification of phenanthroline analogues to ZnS, which has beendemonstrated that the modification to the ZnS can effectively tune the barrier between the work function ofZnS and active layer, reduce the series resistance, better the contact intimate of buffer layer and active layer,and improve the apparent electron mobilities. For the optimized inverted solar cells incorporating thehybrid ZnS-P (ZnS-BCP, ZnS-Bphen, ZnS-Mphen, ZnS-Phen) buffer layer, the PCEs are significantlyimproved from2.95%to7.79,8.00,7.45,7.56%respectively, compared with device based on the singleZnS interfacial layer. These results indicate that the environmentally benign inorganic semiconductor ZnS...