Organic Solar Modules with Good Stability under Ultraviolet Irradiation

One of the most crucial considerations for practical applications of organic photovoltaics (OPV) is the stability under sunlight irradiation. It is necessary to translate the small device stability to the module level. Herein, the photostability of the OPV module with three cells connected in series with a total effective area of 10.8 cm² is presented. The stability of the OPV module is studied under continuous irradiation by a UV light-emitting diode (LED) with integrated UV intensity the same as AM1.5 solar irradiations. As a result, the OPV module achieves good stability under UV light with a half-lifetime of about 1300 h without a UV filter. The lifetime is similar to the small device with the same materials. The series resistance and the encapsulation must be optimized simultaneously. The suitable metal of the external electrode greatly improves the OPV module's performance. In addition, the UV stability of the normal structure is shown to be better than the inverted structure because of the photoinstability of the ZnO layer. Moreover, the UV stability of semitransparent OPV modules is shown to be- similar to the opaque ones.