Plasmonic nanoparticle doping of the active layer for enhancing efficiency and stability in organic photovoltaic devices

Introduction Major goal of this research is the study of new materials and architectures for the enhancement of the photovoltaic properties and the improvement of the stability in organic photovoltaics (OPVs). A factor... [ view full abstract ]

Introduction

Major goal of this research is the study of new materials and architectures for the enhancement of the photovoltaic properties and the improvement of the stability in organic photovoltaics (OPVs). A factor limiting OPVs efficiency is the relatively low absorption in the near-IR range of the organic active layer - constituted by an interpenetrated bulk heterojunction (BHJ) of donor (polymer) and acceptor (fullerene) materials. An advanced approach to elude this problem is the use of plasmonic metallic nanoparticles (NPs), exploiting Localized Surface Plasmon Resonance (LSPR) effects. Consequently, the doped BHJ structural/morphological and interfacial properties must be assessed.

Methods

In-situ Energy Dispersive X-ray Reflectivity and Diffraction are applied jointly with atomic force microscopy to uncover degradation/stabilization effects in plasmonic OPV devices.

Results and Discussion

The characteristics of high efficiency plasmonic OPV devices are investigated. Plasmonic metallic nanoparticles, produced by ultrafast laser ablation in liquids and embedded in the BHJ of the photovoltaic devices result in an increase in the PV efficiency, attributed to improved absorption of the photoactive layer caused by LSPR effects.  Moreover a significant enhancement in lifetime is obtained due to the twofold beneficial effect of NPs incorporation: first the NPs act as stabilizer of the polymer conformational properties, preserving the BHJ donor–acceptor network nanoscale morphology; additionally using gold NPs the cathode buried interface is preserved from photo-oxidation effects. The unconventional structural/morphological cross-monitoring method we used is demonstrated to be a very efficient approach in studying the various aspects that concur in improving the device performances, opening the way to enhanced efficiency and stability OPVs.

References:

[1] B. Paci, G. Kakavelakis, A. Generosi, J. Wright, C. Ferrero, E. Stratakis, E. Kymakis, Solar Energy Materials & Solar Cells, 159, 617–624, 2017.

[2] B. Paci, D. Bailo, V. Rossi Albertini, J. Wright, C. Ferrero, G. D. Spyropoulos, E. Stratakis, E. Kymakis, Adv. Mater., 25, 4760-4765, 2013.

[3] B. Paci, A. Generosi, V. Rossi Albertini, G. Spyropoulos, E. Stratakis, E.; Kymakis, Nanoscale, 4 (23), 7452 – 7459, 2012.

[4]  B. Paci, A. Generosi, D. Bailo, V. Rossi Albertini, G. Spyropoulos, E. Stratakis, E. Kymakis, Adv. Funct. Mater., 21, 3578-3582, 2011.