Abstract
For the past few years, the colorless polyimide (CPI) has been drawn
much attention for its application in transparent electronics, such as
the camera under panel (CUP) in organic light-emitting diode display
(OLED) display which required a high transmittance (Tr%). The high
temperature (even to 450℃) process of the preparation of OLED device may
have huge challenges on the properties of CPI, so we designed a series
of aging test experiments to study the influence of test temperature and
atmosphere on the Tr% of CPI films with structure of
Glass/SiO2/CPI/SiO2. With the increasing
of aging temperate from 430℃ to 450℃ and 470℃, the Tr% of the film
decrease obvious, especially responding the wavelength from 400nm to
600nm. The samples with aging test all had a low Tr% than the sample
without aging. Comparing with the sample without aging, the loss
transmission were 0.22%, 1.42% and 4.82% for the films aging with
430℃, 450℃ and 470℃ in N2 atmosphere, respectively.
Meanwhile, the influence of aging atmosphere on the Tr% was also
researched with nitrogen and air. The film aging with nitrogen had a
higher Tr% than that aging with air, and the loss transmission were
1.22% and 1.42% compared with the sample without aging test. The
properly process temperature and inert atmosphere were selectively
methods to keep a high Tr% of CPI films for preparing transparent
electronics device.