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Luminous‐efficiency improvement of solar‐cell‐integrated high‐contrast organic light‐emitting diode by applying distributed Bragg reflector
Author(s) -
Hsu WeiEn,
Lee ChaoTe,
Lin Hoang Yan
Publication year - 2011
Publication title -
journal of the society for information display
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.578
H-Index - 52
eISSN - 1938-3657
pISSN - 1071-0922
DOI - 10.1889/jsid19.11.847
Subject(s) - distributed bragg reflector , materials science , optoelectronics , oled , luminous efficacy , contrast ratio , optics , full width at half maximum , solar cell , reflector (photography) , quantum efficiency , diode , physics , nanotechnology , light source , wavelength , layer (electronics)
— Solar‐cell‐integrated organic light‐emitting diodes (OLEDs) were fabricated with both high contrast ratio and energy‐recycling ability. However, the luminous efficiency of the integrated devices is reduced to 50% of that of conventional top‐emitting OLEDs. A novel structure to recover the luminous efficiency from 50% to near 85% by applying a distributed Bragg reflector (DBR) made of 20 layers of GaN/AlN was demonstrated. It saves about 40% of the electric power than that of a device without a DBR. The contrast ratio remains high compared to that of conventional OLEDs. In this paper, simulations were conducted first to prove our models and assumptions. Then, two types of thin‐film solar cells — CdTe and CIGS solar cells — were used. They had different contrast ratios as well as viewing‐angle properties. Finally, the emission spectrum was calculated to be 11 nm FWHM, which is narrower than that for the emission spectrum of a typical microcavity OLED and has the advantage of having saturated colors.