ZnO nanoparticles films were prepared via sol-gel process and incorporated into inverted organic photovoltaic devices with a structure of ITO/ZnO/P3HT：PCBM/MoO3/Ag, in which ZnO film served as an electron selective layer. The effects of annealing temperature of ZnO film on the device performance were investigated. When the annealing temperature was 300℃, a well-arranged ZnO thin film was obtained, and the optimized device had doubled short circuit current density （Jsc） and seven-fold higher power conversion efficiency （PCE） compared to the devices without ZnO film. This improvement could be attributed to the enlarged interfacial area of ZnO/active layer and better energy band matching which causes an efficient electron extraction and a decreased interface energy barrier. At particularly high annealing temperature, dramatically increased sheet resistance of indium tin oxide （ITO） was found to cause PCE deterioration. Our finding indicates that it is highly important to investigate both morphology and electrical effects for understanding and optimizing organic photovoltaic （OPV） performance.
Silver nanoparticles(Ag NPs)are synthesized with chemical method,which are introduced into the traditional organic photovoltaic(OPV)structure.The experimental results show that both the optical and photoelectric properties are en-hanced because of localized surface plasmon(LSP)effects of Ag NPs.The advantage of adding Ag NPs behind active layer in incident direction is discussed.We believe this route can avoid absorption shadow and enhance the reusing of transmitted light of active layer.The average short-circuit current(J SC)of the optimum device can be raised from 9.23mA/cm2 to 10.84mA/cm2,and the energy converting efficiency(PCE)can be raised from 3.22% to 3.85%.
Improved power conversion efficiency(PCE)and stability of organic bulk heterojunction(BHJ)solar cells based on poly(2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene)(MEH-PPV)and methanofullerene[6,6]-phenyl C_(61)-butyric acid methyl ester(PCBM)blends are obtained by using ditert butyl peroxide(DTBP)as an additive.The effect of the DTBP contents on the performance of photovoltaic cells is investigated.The results reveal that efficiency enhancement of MEH-PPV:PCBM solar cells can be realized by carefully tuning the contents of DTBP.Compared to the control device,the optimized device with 0.5wt%DTBP additive exhibits enhanced performance with Jsc of(3.51±0.21)mA/cm^(2),FF of(44.45±0.71)%,and PCE of(1.31±0.08)%,increased by 9.3%,8.0%and 22.4%,respectively.The stability of the device is found to be improved by adding 0.5wt%of DTBP.
LI Yan-FangYANG Li-YingQIN Wen-JingYIN Shou-GenZHANG Feng-Ling
