Proceedings of International Conference on Hybrid and Organic Photovoltaics (HOPV16)
Publication date: 28th March 2016
To meet the huge global energy demand and provide secure clean and sustainable energy, solar cells are considered as the most promising route to deplete fossil fuels and environmental pollution. Large scale implementation, however, is still limited by the high processing cost and material consumption. Nanowires (NWs) based Hybrid solar cell (HSC) take the advantage of both fabrication cost reduction and material saving have drawn great attention. In this study, we provide a systematic optical simulation analysis for the design guidelines of GaAs NWs geometrical parameters fully infiltrated in the poly(3-hexylthiophene-2,5-diyl) (P3HT) for optimal HSC performance. Comparative study is carried out about optical absorption of GaAs NWs/air and GaAs NWs/P3HT active layer. It demonstrates that uniform light absorption improvement appears below the absorption edge (650 nm) of organic material whereas above the absorption edge, P3HT serves as a dielectric shell to boost the absorption. Diameter of NWs effectively tunes the absorption peaks due to mode resonance when the filling ratio is below 0.05. As FR increases, high volume percentage of GaAs broadened the absorption spectrum for 80 nm diameter NWs hybrid active layer whereas the destructive interference of HE11 mode resulted in the blue shift for 160 nm case. Mode analyses supplement the absorption transformation with volume percentage. Increase of length of NWs leads to high absorption but threatens device reliability. Therefore, 2 μm is adopted in our investigation. The absorption properties are further analyzed upon the solar illumination and the optimized structure displays 38% of total absorption efficiency. Within the 20 nm diffusion length of organics material a photocurrent of 22.3 mA/cm2 is predicted.