Abstract
In this study, HATCN is coated on flexible PET/indium tin oxide (ITO) substrate as a modified layer and a hole injection layer to improve the hole injection from ITO. Then a blue organic light emitting diode (OLED) can successfully be fabricated without a surface treatment procedure (O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> plasma or UV Ozone treatment). The new blue TADF series fluorescent material is employed as emitting layer with a luminescence wavelength of 456 nm. Also, it has a narrow full width at a half maximum (FWHM) of 26 nm featuring excellent color chromaticity. Quantum dot (QD) photoresist is a perfect color conversion material featuring good color adjustability, narrow emission spectrum, high luminous efficiency, and simple spin-coating processes. In this study, the photoresist mixed with green and red quantum dots is used as a color conversion layer (CCL), and a blue OLED is utilized to excite green and red CCL. To test the material of QD photoresist, it is coated on the substrate of another piece of glass first and then the blue OLED is utilized to remotely excite green and red QD CCL. The fluorescence characteristic of QD photoresist is explored to acquire a spectrum of 528 nm and 620 nm. In the device structure of a blue OLED, the electron-and hole-only current density is compared and the hole transport layer TAPC thickness is adjusted to improve the luminance and efficiency. Finally, green and red quantum dot photoresist is mixed using a proper ratio and then directly coated on the back of the PET/ITO substrate. Furthermore, the thickness of the QD photoresist is adjusted to increase the QD excited fluorescence. The blue OLED and QD CCL was integrated to generate three primary colors, i.e., blue, green, and red. Finally, a flexible white OLED lighting panel is successfully fabricated using simple processes. Moreover, it features high-spectrum stability. The CIE coordinates will not drift with bias, thus, it can resist the voltage variation.
Highlights
WHITE organic light-emitting diodes (WOLED) can be used as general solid state lighting and is light and flexible, offering more convenience for everyday life
MoO3 can be inserted between HATCN and NPB (HATCN/MoO3 (1-5 nm)/NPB), because HATCN/MoO3 can reduce the accumulation of the space charge between indium tin oxide (ITO) electrodes and NPB layer and reduce exciton quenching to extend the organic light emitting diode (OLED) lifetime
The organic layers evaporated on the PET/ITO in the following order: the hole injection layer HATCN/hole transport layer TAPC/emitting layer MADN doped with ν-DABNA/ electron transport and hole blocking layer TPBi
Summary
WHITE organic light-emitting diodes (WOLED) can be used as general solid state lighting and is light and flexible, offering more convenience for everyday life. Quantum dot (QD) features a relatively high fluorescent efficiency with wide-gamut range performance It can be used as color conversion materials. The OLED mainstream manufacturing technologies employ different red green blue (RGB) emitting layers to be mixed to generate the white light. The use of a stable blue OLED and green+red color conversion layers can improve the color stability. In 2020, Zhiping Hu et al published a paper in Nanoscale, concerning the application of QD color conversion film in OLED They utilized blue OLED to excite red and green QD CCL. Many scholars directly utilized green and red luminous QD materials as the emitting layers in OLED to directly fabricate a white-light device [1518]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
