| Summary: | 博士 === 國立臺灣大學 === 物理學系研究所 === 86 === In this thesis, some studies are performed by the optical investigations on PP
Vbased polymers. It is well known that CN-PPV have the interchain emission spe
ciesin the thin film phase. We studis the interchain emission species of CN-PP
Vin dilute solution. The interchain emission species of CN-PPV has a longerlif
etime than the single-chain species. This property is used to probe differente
missve species by time-resolved emission spectrum. Monitoring the fluorescence
spectrum at various delay times after excitation is an essential method to pro
bethe different emission species in the polymer solutioSimilar method is used
toinvestigate another PPV derivatives; PdOPV. It is found that the solubility
ofPdOPV in toluene solution has dramatic temperature dependence around the roo
mtemperature. As being cooled down, the polymer forms aggregates, even in a di
lutesolution. It thus is used to investigate the morphology and emissive speci
es inthe polymer films.In addition, the solubility property is used to sort ou
t polymerswith various chain lengths. The temperature dependent behaviors of P
dOPV in dilutesolution, concentrate solution, and films are investigated. Pres
umably interchainemission species exist in the polymer film, the temperature d
ependence of the single-chain and interchain species is investigated. After se
parated, the polymersshow the same behavior as that of small molecules. In add
ition, their fluorescencealso behave the single-exponential relaxation. Fluore
scent investigations is not only a tool to study dipole-allowed transitionstat
es, but also can be used to probe the triplet states in the polymer films. Her
e,a PPV copolymer with main chain isolated chromophore is used to investigate
the delayfluorescence due to triplet-triplet annihilation. The triplet states
can thus be studiedwithout disturbing the singlet state transitions.
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