SEMICONDUCTOR ADJUSTABLE-COLOR ELECTROLUMINESCENT LIGHT SOURCE Russian patent published in 2003 - IPC

FIELD: light-emitting diodes. SUBSTANCE: light-emitting diode incorporating p-n junction that functions as main radiation source and photoluminescent substance that converts main-source radiation into that with other wavelength has semiconductor gallium nitride base electroluminescent chip and organic photoluminescent region. Semiconductor chip affords multiple-band electroluminescence spectrum incorporating at least two components of which one lies in ultraviolet region and other ones, in visible region. Ultraviolet band is not saturated within wide range of currents while bands of longer waves are saturated at rather high current through device. Organic photofluorescence region possesses high efficiency of ultraviolet light conversion into visible radiation and spectral absorption band of organic material is close to spectral waveform of ultraviolet radiation band of semiconductor chip and partially covers higher-wavelength electroluminescence bands; following materials or their mixtures may be used as organic materials: poly(4.4'-(4"-methyl)triphenylamine) with molecule-mass distribution of Mu = 2332, Mw = 3586, bis(N-(2)- oxybenzylidene)-4-tertiary butyl aniline)zinc; Nile red solid solution in bis(N-2-oxybenzylindene)-4-tertiary butyl aniline )zinc at Nile red concentration of 0.1 to 5 mass percent. Color of light-emitting diode at light intensity as high as L>300 mcd with forward current I_f≈20 mA is adjusted both during its manufacture by adding various absorbing and photoluminescent materials and in the course of operation by varying parameters of supply voltage. EFFECT: enhanced capabilities of adjusting light-emitting diode color. 13 cl, 8 dwg