Abstract
The spectral properties of a conjugated polymer poly [2-methoxy-5-(2-ethylhexyloxy)-1, 4-phenylenevinylene] (MEH-PPV) in benzene have been studied intensively. The fluorescence spectra for MEH-PPV, under low concentrations, have shown two peaks around 560nm and 600nm, which could be attributed to the monomer and excimer states respectively. In our earlier communication, we had shown that MEH-PPV alone could produce amplified spontaneous emission (ASE) only in its excimeric state (600nm). The spectral properties of 5nm size of CdSe (core) quantum dots have been investigated. The fluorescence spectra of CdSe core in benzene showed only one band at 590nm. Mixtures made of MEH-PPV and CdSe (core) quantum dots have been utilized for studying the amplified spontaneous emission characteristics (ASE) in an organic solution under laser excitation. When the mixture was pumped by the third harmonic of Nd:YAG (355nm), we observed two ASE peaks; one at 575nm and another at 595nm. These ASE peaks could arise from the monomer and excimer states of MEH-PPV. This is perhaps the first report on the influence of quantum dots on the laser from the conjugated polymer MEH-PPV, in liquid solution.
•The Spectral properties of MEH-PPV under different concentrations were studied.•The Spectral properties of CdSe quantum dots under different concentrations were studied.•The ASE from MEH-PPV found to be in excimeric state.•The influence of CdSe quantum dots on the ASE from MEH-PPV under different concentrations was discribed.•The ASE spectra had shown two peaks attributed to the monomeric and excimeric states.