The performances of organic optoelectronic devices, such as organic light emitting diodes and polymer solar cells,have rapidly improved in the past decade. The stability of an organic optoelectronic device has become a key problem for further development. In this paper, we report one simple encapsulation method for organic optoelectronic devices with a parafilm, based on ternary polymer solar cells(PSCs). The power conversion efficiencies(PCE) of PSCs with and without encapsulation decrease from 2.93% to 2.17% and from 2.87% to 1.16% after 168-hours of degradation under an ambient environment, respectively. The stability of PSCs could be enhanced by encapsulation with a parafilm. The encapsulation method is a competitive choice for organic optoelectronic devices, owing to its low cost and compatibility with flexible devices.
There is a rising prospective in harvesting energy from the environment,as in situ energy is required for the distributed sensors in the interconnected information society,among which the water flow energy is the most potential candidate as a clean and abundant mechanical source.However,for microscale and unordered movement of water,achieving a sustainable direct-current generating device with high output to drive the load element is still challenging,which requires for further exploration.Herein,we propose a dynamic PN water junction generator with moving water sandwiched between two semiconductors,which outputs a sustainable direct-current voltage of 0.3 V and a current of 0.64μA.The mechanism can be attributed to the dynamic polarization process of water as moving dielectric medium in the dynamic PN water junction,under the Fermi level difference of two semiconductors.We further demonstrate an encapsulated portable power-generating device with simple structure and continuous direct-current voltage output of 0.11 V,which exhibits its promising potential application in the field of wearable devices and the IoTs.
TiO2 thin films deposited by magnetron sputtering possess excellent optical transmittance,high refractive index,good adhesion and chemical stability.In this manuscript,TiO2 thin films deposited by magnetron sputtering was used for the first time as an electron extraction layer in inverted polymer solar cells(IPSCs),and the effect of the TiO2 thickness on the photovoltaic performance of P3HT:PC61BM IPSCs was investigated.The highest PCE value of 3.75%was obtained when the thickness of TiO2thin films was in the range between 42 nm and 73 nm.The absorption properties,morphology and structure of the TiO2 films were characterized by UV-Vis spectroscopy,SEM and Raman spectroscopy,and were related to the device performance of P3HT:PC61BM IPSCs.The results indicate that TiO2 films deposited by magnetron sputtering are an excellent electron extraction layer for IPSCs.
A series of P3HT:PC71BM polymer solar cells(PSCs)with different PIDTDTQx doping concentrations were fabricated to investigate the effect of the PIDTDTQx as a complementary electron donor on the performance of PSCs.The power conversion efficiency(PCE)of the optimized ternary blend PSCs(with 2 wt%PIDTDTQx)reached 3.87%,which is 28%higher than that of the PSCs based on P3HT:PC71BM(control cells).The short-circuit current density(Jsc)was increased to 10.20 m A/cm2compared with the control cells.The PCE improvement could be attributed to more photon harvest and charge carrier transport by appropriate doping PIDTDTQx.The energy transfer from P3HT to PIDTDTQx was demonstrated from the 650 nm emission intensity decrease and the red-shifted emission peaks from 725 nm to 737 nm along with the increase of PIDTDTQx doping concentrations.
