Efficient Polymer Solar Cells Using Surface Plasmon Resonance Effect Based On AgAl Alloy Nanostructures

Silicon-based solar cells have developed a mature technology and widely been commercial application.However,silicon based solar cells show high price and lack of flexibility and transparence,which limit its application in special field.Polymer solar cells?PSCs?have attracted great attention because of their unique advantages,such as solution-processed fabrication,light weights,mechanical flexibility,translucence,and large-scale production at low cost.The efficiency of polymer solar cells has exceeded 11%,which gradually approach to the commercial application.However,polymer semiconductor materials show short diffusion distance of excitons and low mobility,which limits the thickness of photoactive layer and so inhibits the light absorption.The surface plasmonic resonance effect of noble metal nanostructures has been demonstrated an effective way to improve the light absorption.However,the more efficient strategy to improve efficiency and stability of cells still need to be further developed.In this thesis,the power conversion efficiency and stability of PSCs have been investigated using interface modification method and the surface plasmonic effect based on AgAl alloy and Au nanostructures.The detail content is as follow:?1?AgAl and Ag nanostructures have been inserted into MoO₃ hole-transport layer using thermal evaporation,and the surface plasmonic effect of AgAl and Ag nanostructures can be adjusted by controlling the isolation thickness of MoO₃ layer and nominal thickness of AgAl and Ag layer.The efficiency of PSCs with MoO₃?8 nm?/AgAl?3 nm?/MoO₃?1 nm?layer got the best PCE of 9.79%,which is higher than PCE?8.55%?of Ag nanostructures based PSCs.The surface plasmonic effect of AgAl nanostructures can be well kept using only 1 nm thickness of MoO₃ spacer.Furthermore,the PCE of PSCs with AgAl and Ag nanostructures remains 60%and 26%of the original PCEs aging for 120 days,indicating AgAl alloy nanostructures based PSCs show better stability.?2?Au nanostructures were further inserted into the structure ofMoO₃/AgAl/MoO₃ using thermal evaporation,which can realize the synergistic effect of AgAl and Au nanostructures by optimizing thickness of MoO₃ isolation layer.The light absorption effect of cells was extended and PSCs with the structure of MoO₃?8 nm?/AgAl?3 nm?/Au?1 nm?/MoO₃?2 nm?can reach up to 10.3%of PCE using AZO as electron transport layer.