Mater.Phys.Mech.(MPM)
No 2, Vol. 18, 2013, pages 143-147

TEMPERATURE STABILITY OF COLORED LED ELEMENTS

K.A. Vinogradova, L.A. Nikulina, S.S. Braslavskii, E.A. Solovieva,
K.D. Mynbaev, V.I. Nikolaev, A.E. Romanov, V.E. Bougrov

Abstract

Temperature stability of the optical power output of colored (blue-red) light emitting diode (LED) elements is considered. It is shown that LEDs based on blue 455 nm semiconductor chips have the best thermal stability, which is expressed in just 4 % of optical power losses with LED board temperature increasing from 25 C up to 50 C. The value of optical power losses for red chips emitting at 660 nm and 730 nm were 7 % and 11 %, respectively, while devices based on 455 nm blue chips and red nitride phosphors with 2 % and 8 % phosphor concentration showed losses of 4 % and 8 %, respectively. Wall plug efficiency of the studied samples demonstrated a similar trend with the temperature increasing as the optical power did.

Keywords: LEDs; temperature stability; greenhouse emitters; phosphors

full paper (pdf, 1344 Kb)