March 15, 2011...Osram Opto Semiconductors reports that it has set a new laboratory record of 142 lm/W for the efficiency of a warm white LED light source. The LED with a correlated color temperature (CCT) of 2755 K achieves a color rendering index (CRI) of 81. Measurements were taken under standard conditions: room temperature and pulsed mode at an operating current density of 350 mA/mm2.
According to the company, the peak value of 142 lm/W was measured under standard conditions. It was achieved at a color perception that the company says very closely matches that of a classic incandescent lamp (color coordinates cx 0.46/ cy 0.41 on the Planckian curve). Osram Opto says that the increase in efficiency was enabled through the combining of new procedures in thin-film and UX:3 chip technologies and in conversion. Further development reportedly benefited from knowledge of epitaxial growth, thin-film chip architectures, conversion processes and package technologies.
¡°If we explore this technical approach further and allow deviations from the Planckian curve we should even now be able to achieve higher efficiency values of up to 160 lm/W for a correlated color temperature of 3000 K (cx 0.45/ cy 0.44)¡±, said Dr. Norwin von Malm, Predevelopment Manager at OSRAM Opto Semiconductors. ¡°If we apply this approach to a 2 mm? chip we can improve efficiency by a further 10 to 15 percent for the same operating current. We would then expect 180 lm/W for a pure warm white LED and good color rendering