ORGANIC PHOTOVOLTAIC SOLAR CELLS USING THIN TUNGSTEN OXIDE AS INTERLAYER ANODE CONTACT MATERIAL

摘要

Recent results for single junction bulk heterojunction OPV devices show markedly improved efficiencies above 8 %.However, long term stability remains an open issue. The common ITO anode contact in combination with PEDOT:PSS isknown as a severe source of degradation. We investigate P3HT:PCBM based organic solar cells using an alternativePEDOT:PSS free anode contact structure using a thin WO_3 interlayer for hole extraction: Glass / ITO / WO_3 (0 –20 nm) / P3HT:PCBM/Al. We report on parameter variation of the device preparation with respect to WO_3 interlayerthickness. RF sputter deposition from ceramic ITO and reactive DC sputter deposition from metallic W targets was used fordeposition of the Glass / ITO / WO structure. By comparison of the solar cell performance with the conventional devicestructure, the proof-of-principle and applicability of these potentially long-term stable oxide interlayer contact asPEDOT:PSS replacements is demonstrated. The dependence of solar cell parameters on the oxide layer thickness is analyzed.