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%.
ZnO nanoparticles films were prepared via sol-gel process and incorporated into inverted organic photovoltaic devices with a structure of ITO/ZnO/P3HT:PCBM/MoO_3/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(J_(SC)) 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.
We report the enhanced performance of organic solar cells(OSCs) based on regioregular poly(3-hexylthiophene)(P3HT) and methanofullerene [6,6]-phenyl C61-butyric acid methyl ester(PCBM) blend by using dihydroxybenzene as additive in the active layer.The effect of the content of the additives on electrical characteristics of the device is studied.The device with 0.2 wt% dihydroxybenzene additive achieves the best power conversion efficiency(PCE) of 4.58% with Jsc of 12.5 mA/cm2,Voc of 0.65 V,and FF of 66.6% under simulated solar illumination of AM 1.5G(100 mW/cm2),compared with the control device with PCE of 3.39%(35% improvement compared with the control device).The XRD measurement reveals that the addition of additives induces the crystallization of P3HT and establishes good inter-network to increase the contact area of donor and acceptor,and then helps charge to be effectively transferred to the electrode to reduce the chance of recombination.All evidences indicate that the dihydroxybenzene is likely to be a promising new type additive that can enhance the performance of organic bulk heterojunction solar cells.
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.
An air-stable photovoltaic device based on znic oxide nanoparticles (ZNP) in an inverted structure of indium tin oxide (ITO)/ZnO/poly (3-hexylthiophene) (P3HT): [6,6]-phenyl C61-butyric acid methyl ester (PCBM)/MoO3/Ag is studied. We find that the optimum thickness of the MoO3 layer is 2 nm. When the MoO3 blocking layer is introduced, the fill factor of the devices is increased from 29% to 40%, the power conversion efficiency is directly promoted from 0.35% to 1.27%.The stability under ambient conditions of this inverted structure device much is better due to the improved stability at the polymer/Ag interface. The enhancement is attributed to the high carriers mobility and suitable band gap of MoO3 layer.
The effect of a new interfacial buffer layer material,rhenium oxide(ReO3),on the performance of polymer solar cells based on regioregular poly(3-hexylthiophene)(P3HT) and methanofullerene [6,6]-phenyl C61-butyric acid methyl ester(PCBM) blend is investigated.The effect of the thickness of the oxide layer on electrical characteristics of the device is also studied.Compared with traditional devices,by inserting a 10 nm-thick ReO3 as the anode buffer layer,a power conversion efficiency(PCE) of 2.8 %(a 37% improvement compared with the control devices) can be obtained with Jsc of 13.6 mA/cm2,Voc of 0.45 V,and a fill factor(FF) of 53.6% under the simulated AM1.5 G 100 mW/cm2 illumination in air.It is indicated that ReO3 can be used as an effective buffer layer to enhance the polymer bulk heterojunction(BHJ) photovoltaic cell efficiency.
