Silver nanowire networks on polydimethylsiloxane for organic and perovskite solar cell electrodes

Güner, Elif Özlem
Transparent and conductive electrodes are widely used in optoelectronic devices. The most prominent and commercial transparent conductive electrode is indium tin oxide (ITO). However, there is an increasing demand to replace ITO with alternative materials due to inherent drawbacks of ITO such as its cost, brittleness and scarcity of indium. Silver nanowire (Ag NW) networks are among the best candidates to replace ITO with their excellent optoelectronic and mechanical properties. Ag NW networks have already been demonstrated as electrodes in a wide range of applications such as transparent heaters, flexible displays, stretchable electronics and photovoltaic devices. However, there are still some challenges in obtaining a uniform Ag NW network on different substrates. In this thesis, a polydimethylsiloxane (PDMS) assisted transfer method was developed to overcome this problem. Ag NWs synthesized via polyol process were spray coated onto glass substrates in network form. PDMS was then casted onto Ag NW networks and peeled off following curing to transfer Ag NWs onto PDMS surface. This transparent Ag NW embedded PDMS substrates were then used as electrodes in both organic and perovskite based solar cells. First, a semi-transparent organic solar cell (OSC) with Ag NW/PDMS electrodes was demonstrated using a commercially available and a novel polymer as the photoactive layers. Power conversion efficiencies of above 2% and 3% was obtained from these cells with architectures of glass/ITO/ZnO/P3HT:PCBM/PEDOT:PSS/Ag NW/PDMS and glass/ITO/ZnO/PBDB-T:ITIC/PEDOT:PSS/Ag NW-PDMS, respectively, under AM 1.5G illumination conditions. Secondly, a mesoporous perovskite solar cell was demonstrated using Ag NW/PDMS electrodes and commercially available photoactive layers. The cells based on glass/FTO/k-TiO2/m-TiO2/Perovskite/Spiro-OMeTAD/Ag NW/PDMS architecture showed a power conversion efficiency of 6.5% under AM 1.5G illumination conditions. PDMS assisted transfer method utilized herein offers a simple, solution-based and transparent alternative to evaporation method for the formation of solar cell electrodes.
Citation Formats
E. Ö. Güner, “Silver nanowire networks on polydimethylsiloxane for organic and perovskite solar cell electrodes,” Thesis (M.S.) -- Graduate School of Natural and Applied Sciences. Metallurgical and Materials Engineering., Middle East Technical University, 2019.