title: Lanthanum Hexaboride As Novel Interlayer for Improving the Thermal Stability of P3HT:PCBM Organic Solar Cells.
abstract: For efficient organic photovoltaic (OPV) solar cells, a low work function electrode is necessary to enhance the built-in voltage of the active layer, thereby improving the overall efficiency. Calcium is often used for this purpose in the laboratory; however, its development on a larger scale is impaired by its high reactivity with oxygen and water and the resulting low stability of solar cells under operation. The influence of a novel interlayer, lanthanum hexaboride (LaB6), on the electronic properties of OPV is studied in this work. Similarly to calcium, when LaB6 is used as an interlayer, it enhances the built-in voltage in the device, leading to a higher fill factor (FF) and optimal open circuit voltage (V(oc)). As a result, optimized LaB6-based devices present significantly improved power conversion efficiencies. More importantly, while calcium/aluminum (Ca/Al) and aluminum (Al) cathodes lose their capacity to enhance the internal electrical field during thermal aging, the LaB6/aluminum (LaB6/Al) electrode remains stable. This remarkable effect results in a highly stable V(oc) and flat-band potential during aging.
authors.affiliation: Univ. Bordeaux, IMS, UMR 5218 , F-33405 Talence, France.|CNRS, IMS, UMR 5218 , F-33405 Talence, France.|Bordeaux, INP, IMS, UMR 5218 , F-33405 Talence, France.
authors.forename: Sylvain
authors.initials: S
authors.lastname: Chambon
authors.affiliation: Univ. Bordeaux, IMS, UMR 5218 , F-33405 Talence, France.|CNRS, IMS, UMR 5218 , F-33405 Talence, France.|Bordeaux, INP, IMS, UMR 5218 , F-33405 Talence, France.
authors.forename: Yolande
authors.initials: Y
authors.lastname: Murat
authors.affiliation: Univ. Bordeaux, IMS, UMR 5218 , F-33405 Talence, France.|CNRS, IMS, UMR 5218 , F-33405 Talence, France.|Bordeaux, INP, IMS, UMR 5218 , F-33405 Talence, France.
authors.forename: Guillaume
authors.initials: G
authors.lastname: Wantz
authors.affiliation: Univ. Bordeaux, IMS, UMR 5218 , F-33405 Talence, France.|CNRS, IMS, UMR 5218 , F-33405 Talence, France.|Bordeaux, INP, IMS, UMR 5218 , F-33405 Talence, France.
authors.forename: Lionel
authors.initials: L
authors.lastname: Hirsch
authors.affiliation: Univ. Bordeaux, IMS, UMR 5218 , F-33405 Talence, France.|CNRS, IMS, UMR 5218 , F-33405 Talence, France.|Bordeaux, INP, IMS, UMR 5218 , F-33405 Talence, France.
authors.forename: Pascal
authors.initials: P
authors.lastname: Tardy
keywords: interlayer; lanthanum hexaboride; lifetime; organic photovoltaic; stability; thermal degradation