Novel concept for tunable solid state white light LED sources

At the Institute of Physics have developed a completely novel material family which can be used for these smart lighting sources construction. This material concept is based on ternary sulfides of general formula KxNa1-xLuS2 doped by Eu2+ ions and the usage of these phosphors is covered by patents. The main advantage of this material family is the possibility of efficient excitation by two LEDs (one near UV nad the other blue) at the same time due to broad absorption spectrum of Eu2+ ions given by the allowed 4f – 5d transition. Under these excitations a broad emission can be achieved covering broad spectral range in visible part of the electromagnetic spectrum. It means that no mixture of phosphors is required for circadian light source preparation.

Technical parameters

Single host material with two different luminescent centers, A1 and A2

Single UV excitation (360 nm) – center A1 is excited and emits

Part of emission light from A1 is absorbed by A2 which emits at lower energies

Only by single excitation at 360 nm, white light can be obtained in single phosphor

Different CCT temperatures can be reached just by using different A1, A2 concentrations


Single host material based on KxNa1-xLuS2 doped by only activator Eu2+

Two different excitation diodes are used to excite the phosphor – nearUV and blue

Tunability is achieved by changing the ratio between these two excitation diodes

Furthermore different CCT temperatures can be obtained by modifying K/Na ratio in KxNa1-xLuS2


Mr. Oskar Lazansky | e-mail: | mobil: +420 725 015 339




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