![]() The experimental results confirmed the high sensitivity of the MEH–PPV solution to low-dose irradiation at low concentrations. Recently, a study was conducted on the gamma-irradiation effects on the spectral properties of poly (MEH–PPV) dissolved in tetrahydrofuran (THF). The MEH–PPV performed just as efficiently as the conventional laser dye rhodamine 6G. In 1992, Moses produced a laser action using a liquid state conjugated polymer (MEH–PPV), operating in the portion of the yellow/red wavelength. In contrast, conjugated polymers can emit fluorescence and laser light as neat solid films, even at higher concentrations. ![]() Many fluorescent organic molecules such as laser dyes reveal a very low quantum yield at higher concentrations because of reabsorption and are unable to emit laser light, especially in a solid film configuration. Conjugated polymers possess characteristics of broadband emission appropriate for tunable lasers, with strong powers of absorption and emission, a large Stokes shift, high luminescence, and substantial quantum yield. These macromolecules show spectral properties similar to those of optically active small organic molecules, such as laser dyes. Ĭonjugated polymers can be excited via charge injection or photo-excitation. Conjugated polymers have also been investigated as potential radiation detectors. Among conjugated polymers, the polyphenylene-vinylene (PPV) family has drawn considerable attention for its significant optical and electrical properties. Light emitting diodes (LEDs) based on conjugated polymers have generated great interest because of their potential applicability to large areas and flat panel displays, their ability to operate at relatively low voltage, their low cost, and their easy fabrication. This could be the first report on the effect of gamma radiation on the ASE properties of conjugated polymers. This shift in the luminescence and ASE spectra could be a response to the conformational disorders such as gamma irradiation-induced polymer crosslinking, which was verified using Raman spectra, FTIR, and swelling experiments. The result revealed a dramatic blue shift of the fluorescence and the ASE spectra after gamma irradiation. The ASE profiles of the CPs in THF were obtained under the high power excitation of a Nd:YAG laser (355 nm), pre- and post-radiation. To explore these changes, gamma radiation, in the range of 2–50 kGy, was used to maintain the temperature at 5 ☌ constant for all doses at a dose rate of 12.67 kGy/h, using a 60Co gamma ray. Gamma irradiation strongly affected the photophysical properties of these CPs. In this paper, we investigate the effects of gamma (γ) radiation on the spectral and mplified spontaneous emission (ASE) properties of two conjugated polymers (CPs) viz., poly (MEH–PPV) (CPM) and poly (BEHP- co-MEH–PPV) (BMP) in tetrahydrofuran (THF).
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