The Influences Of Annealing And Function Layers On The Performance Of P3HT:PCBM Solar Cell

In21st century, human beings are facing an important challenge of the sustainable development. Solar cells have been paid more and more attention because of energy shortage and environmental pollution in modern society. Recently, the power conversion effieieney of organic solar cells based on P3HT:PCBM has already broken through8%.We select P3HT:PCBM to research the performance of annealing treatment, inserting function layer in bulk heterojunction (BHJ) solar cells.It contains two aspects as follows.1. First,we fabricated devices with different thickness,and the structure of ITO/PEDOT:PSS/P3HT:PCBM/A1. Experimental results show that the performance of device is the best while the speed of Spin Coating is2000RPM, the voltage,short-circuit current, fill factor, and power conversion efficiency was0.60V,3.35mA/cm2,37.80%,0.77%respectively.Second,we used different time to anneal the devices at150℃in low vacuum, experimental results show that the device shows the best performance while the time is30min,with the increase of Jsc from3.19mA/cm2to6.44mA/cm2,Voc from0.59V to0.62V, FF from37.75%to55.29%, PCE from0.71%to2.21%. In order to avoid the anode contacting with the acceptor directly, we incorporated a P3HT layer between PEDOT:PSS and P3HT:PCBM,which enhances absorption of incident light,increases the donor-acceptor interfacial area and provides transport pathways for charge carriers(holes). But,the pre-coated P3HT film is dissolved to P3HT:PCBM active layer partly,which damages the interpenetrating network structure, resulting in a bad device performance.2. We uesd ZnO NPs in certain particle size as modified layers to study influences on the performance of the solar cells by changing the position of ZnO NPs in the device structure.First,ZnO NPs is used as anode modified layer in the BHJ polymer solar cells,and the structure of ITO/ZnO NPs/PEDOT:PSS/P3HT:PCBM/Al. Light scattering occurs when the incident light through the ZnO NPs,which enhances absorption of incident light.Experimental results show that the device shows the best performance while the speed of Spin Coating is3000RPM, In this way, the short-circuit current,fill factor, and power conversion efficiency can be effectively increased by11.8%,7.81%and0.5%. Second,ZnO NPs has excellent electron transporting ability, which is used as cathode modified layer in the BHJ polymer solar cells,and the structure of ITO /PEDOT:PSS/P3HT:PCBM/ZnO NPs/Al.Experimental results show that the performance of the device is improved, the short-circuit current, fill factor, and power conversion efficiency can be effectively increased by11.57%,1.19%and0.17%.