2-3차원 경계에서 고분자 나노 박막의 광학적 특성 = The optical properties of polymer nano films at the thickness range between two and three dimension

다국어 초록 (Multilingual Abstract)

The polymer electro-optic device with nano-meter scale thick film has been proposed. The electro-optic performance has been investigated for the P(VDF-TrFE 70:30) Langmuir Blodgett film with its thickness in the crossover region between two and three dimensions.
P(VDF-TrFE) powder sample was dissolved in dimethyl sulfoxide (DMSO) with a concentration of 0.05wt%. The polymer solution was spread on the ultrapure(18MΩ) water subphase in the LB trough with a working area of 1,000㎠ using a micropipet. The monolayers on the water surface are deposited on the ITO coated glass substrate at room temperature at a surface pressure of 5 mN/m using horizontal transfer method.
Atomic force microscopy showed that annealing the thinnest films of crystallized nanomesa patterns, and ML increases, the percentage of the total area of nanomesa increased.
The thickness of the film was measured by the ellipsometer. ML thickness increases linearly. The thickness of 1ML 2.37nm was confirmed.
The devices for electro-optic measurement were fabricated by the following process: depositing LB layer on the ITO coated glass substrate, annealing the LB copolymer LB film, topping 6nm silicon nitride layer for preventing electrical short, vacuum coating with 200nm aluminum layer by thermal evaporation. The E/O coefficient was measured by using conventional simple reflection method proposed by Teng etalin 1990.
The E/O coefficient measured results of depending on the thickness, P(VDF-TrFE) LB films of more than 15ML depend on a finite-size effect is the three-dimensional characteristics. P(VDF-TrFE) LB films of Less than 10ML do not depend on a finite-size effect and are the two-dimension characteristics. The boundary of P(VDF-TrFE) LB films of two dimension and three dimension are 10ML. And the electro-optic effect is the most efficient after annealing 10ML.