Abstract
•Silver nanoparticles embedded PANI is used as buffer layer for ITO/AgNPPANI/PANI/Al solar cell.•Buffer layer significantly improves the diode parameters, stability and photovoltaic response.•Improvements are due to reduction in interfacial trap states and enhancement in dipole-moment.•0.5% Concentration of AgNP in PANI buffer layer shows the most optimum photovoltaic response.
The role of silver nanoparticles (AgNP) in polyaniline (PANI) as a buffer layer for ITO/AgNP-PANI/PANI/Al solar cell was investigated. It is observed that AgNP-PANI buffer layer significantly improves the electrical parameters such as diode-ideality factor, series-resistance, energy-barrier height, and shunt-resistance as a growing function of AgNP concentration. On-the-other hand oppose to the dark current-voltage response, 0.5% concentration of AgNP in buffer layer shows the most optimum photovoltaic response and cause to increase the power conversion efficiency (PCE) nearly 5 times compared to same solar cell without buffer layer. Such improvements in electrical parameters can be interpreted as the reduction in interfacial trap states as well as enhancement in interfacial dipole-moment by AgNP embedded buffer layer for given photovoltaic device. While, the observed optimum photovoltaic behavior at 0.5% AgNP concentration is may be due to the trade-offs between gains and losses for optical absorption enhancement, self-absorption heating and interface recombination losses respectively. It is also observed that the AgNP embedded PANI buffer layer approach is an effective solution to lower the photovoltaic degradation and hence improves the stability of the photovoltaic devices.