High-Speed
Visible Light Communication Using Phenothiazine/Dimesitylborane
Derivatives as Color Conversion Materials in Semipolar Micro-LED-Based
White-Light Systems
posted on 2024-02-02, 13:34authored byAnnada
Sankar Sadhu, Li-Yin Chen, Yi-Hua Pai, Chung-An Hsieh, Hao-Wu Lin, Chi-Wai Chow, Hao-Chung Kuo
Visible light communication (VLC) has emerged as a cutting-edge
high-speed communication technology, poised to meet the surging capacity
demands of 6G networks. Micro-light-emitting diodes (μLEDs)
are considered as the light sources for achieving high-speed VLC,
distinguished by their remarkable modulation bandwidths. However,
achieving broadband white light emission hinges on the utilization
of color-conversion materials with wide emission spectra. The transmission
speed of the white-light system is inherently constrained by the characteristics
of these color-conversion materials. In this work, we demonstrate
CC-MP7 and CC-MP8, two derivatives of phenothiazine/dimesitylborane,
as color conversion materials in a semipolar (20–21) micro-LED-based
white-light system for high-speed VLC. The color conversion layers
possess wide emission spectra, enabling them to achieve excellent
color rendering performance when combined with blue micro-LEDs. CC-MP7
and CC-MP8 demonstrate rapid photoluminescence decay characteristics,
thereby enhancing the modulation bandwidth of the color-conversion
layer in the white-light system. The resulting bandwidths achieved
by CC-MP7 and CC-MP8 are 210 and 240 MHz, respectively, which represents
an approximately 45-fold increase compared to ordinary phosphors.
By combining semipolar (20–21) micro-LEDs with CC-MP7 and CC-MP8,
the resulting white-light systems exhibit correlated color temperatures
of 6860 and 7500 K, CIE coordinates of (0.3009, 0.3577) and (0.2958,
0.3129), and color-rendering indexes of 80 and 85, respectively. Furthermore,
both systems offer high bandwidths of 1063 and 1084 MHz with the data
rates of 1.72 Gbps and 1.74 Gbps using non-return-to-zero on–off
keying (NRZ-OOK) format, respectively, indicating the significant
potential of CC-MP7 and CC-MP8 for practical applications in VLC.