Influence of Electrode Interfacial Buffer Layers on Thermal Stability of P3HT:PC61BM Solar Cells

The high-temperature thermal stability of solution-processed polymer solar cells is a key issue that determines the feasibility of further thermal encapsulation processes, such as thermal lamination or hightemperature atomic layer deposition. In this article, polymer solar cells with poly(3, 4-ethylenedioxythiophene)/poly(styrenesulfonate) (PEDOT:PSS) or MoO3 as the anode buffer layer (ABL) and ZnO or LiF as the cathode buffer layer (CBL) were fabricated with a device structure of indium tin oxide (ITO)/ABL/poly(3-hexylthiophene): phenyl- C61- butyric acid methyl ester (P3HT:PC61BM)/CBL/Al. Device performances, especially the hightemperature thermal stability of the devices, were studied in detail. The results indicated that the thermal stability of the organic solar cells was highly dependent on the buffer layer material. Devices with MoO3 as ABL and ZnO as CBL showed high thermal stability at a temperature of 120-150 , which ensures the possibility of subsequent thermal processing. In addition, the use of ZnO as the cathode buffer layer could also improve longterm device stability.