Study of the Stability of Encapsulated and Non-encapsulated Polymeric Photovoltaic Cells under Sun and Indoor illumination

Identifier:  TFM:1186

Handle: https://hdl.handle.net/20.500.11797/TFM1186

Authors:  Serantes Melo, Marta

Abstract:
In this study, we analyze the degradation behavior of conventional polymeric solar cells (PSCs) under both solar and indoor illumination. In addition, we compare the results obtained with encapsulated and non-encapsulated devices. The performance of the PTB7:PC70BM-based cell showed an initial efficiency of 8.4 % under AM1.5G solar illumination and 12.0% under the LED one. The work describes first the results obtained after the measurement and analysis of the degradation process, performed by a current density – voltage (J–V) characteristic curve study, taking into account 4 performance parameters: power conversion efficiency (PCE), short circuit current density (JSC), open-circuit voltage (VOC) and fill factor (FF). The PCE of encapsulated devices under LED illumination decreased a 20% of the initial PCE after 624 h, while under sun illumination it lost a 90 % after 900 h. After this an impedance spectroscopy study was performed to analyze the internal evolution of the cell under solar AM1.5G illumination, getting to the conclusion that the active layer is the most affected when being encapsulated.