We investigate the amplified spontaneous emission （ASE） from an Ag-backed poly[2-methoxy-5-（2＇-ethylhexyloxy）- 1,4-phenylenevinylene] （MEH-PPV） film with different film thicknesses. The ASE characteristics of Ag-backed MEH- PPV films with different thicknesses show that increasing the film thickness can reduce the influence of the Ag cladding. The threshold, the gain, and the loss of the device with a thickness of 170 nm are comparable to those of a metal-free device. The lasing threshold of this device is about 7.5 times that of a metal-free device. Our findings demonstrate that Ag-backed MEH-PPV film with an appropriate thickness can still be a good polymer gain material for the fabrication of solid-state lasers.
In this work, performance enhancements of amplified spontaneous emission （ASE） from poly[2-methoxy-5-（2＇- ethyl-hexyloxy）-l,4-phenylene vinylene] （MEH-PPV） have been achieved via solvent vapour treatment. Correlations between the morphology of the film and the optical performance of polymer-based ASE are investigated. The active layers are characterised by atomic force microscopy and optical absorption. The results show that the solvent-vapour treatment can induce the MEH-PPV self-organisation into an ordered structure with a smooth surface, leading to enhanced optical gain. Thus the solvent-vapour treatment is a good method for improving the optical properties of the MEH-PPV.
In this work, enhanced poly（3-hexylthiophene）：[6,6]-phenyl-C61-butyric acid methyl ester （P3HT：PCBM） bulk- heterojunction photovoltaic devices are achieved via slow-solvent-vapour treatment. The correlations between the morphology of the active layer and the photovoltaic performance of polymer-based solar cell are investigated. The active layers are characterized by atomic force microscopy and optical absorption. The results show that slow-solvent- vapour treatment can induce P3HT self-organization into an ordered structure, leading to the enhanced absorption and efficient charge transport.
In the process of fabrication of polymer photovoltaic （PV） devices, poly （3, 4-ethylenedioxythiophene）： poly（styrenesulfonate） （PEDOT：PSS） thin film, acting as an anode buffer layer, is spin-coated under the action of an electric field. The PV devices with a PEDOT：PSS layer spin-coated under the action of a static electric field exhibit improved short-circuit current density （Jsc） and power conversion efficiency （PCE）. The investigation of morphology shows that the appropriate intensity of the electric field can increase the roughness of the surface of the PEDOT：PSS layer, which results in improved contact between the anode and hole transport layer and thus enhances the Jsc of the devices. Chemical analysis is also provided by x-ray photoelectron spectroscopy （XPS） spectra.
We investigate the effect of a metallic electrode on the ability for poly[2-methoxy-5-（2＇-ethylhexyloxy）-1,4- phenylene vinylene] （MEH-PPV） film to undergo amplified spontaneous emission （ASE）. The threshold of the device with Ag cladding is about 10 times greater than that of a metal-free device, but metal such as Al completely shuts off ASE. The ASE recurs when a thin spacer layer, such as a few nanometers of SiO2, is introduced between the MEH-PPV film and the Al cladding. Compared with the Cu or Al electrode, the Ag cladding is most suited to serve as an electrode with its low optical loss due to its high work-function and reflectivity.
