Osram laboratory warm white LED light efficiency reaches 142lm / W

March 16, 2023

Recently, according to foreign media reports, OSRAM Opto Semiconductors successfully increased the luminous efficiency of warm white LED light sources to 142 lm / W, setting a new laboratory record. At a correlated color temperature (CCT) of 2755 K, the color rendering index (CRI) of the LED is as high as 81. These values were measured under standard conditions: at room temperature, using a pulse mode with an operating current density of 350 mA/mm2.

Bright and efficient warm white light is especially important for residential lighting applications. The laboratory solution for warm white LEDs demonstrates the enormous potential of these energy-efficient semiconductor light sources: the peak value of 142 lm/W is successfully measured under standard conditions, and the color perception is also very close to that of traditional incandescent lamps (color coordinates cx 0.46 on Planck's trajectory / Cy 0.41).

Dr. Norwin von Malm, former development manager of Osram Opto Semiconductors' German headquarters, said: "If we further develop in this direction and allow deviations from the Planckian trajectory, we are able to achieve higher luminous efficacy values, up to 160 at a correlated color temperature of 3000 K. Lm/W (cx 0.45 / cy 0.44). If this technology is applied to a 2 mm2 chip, the operating efficiency can be increased by 10% to 15% under the same operating current, that is, the pure warm white LED The efficiency is expected to reach 180 lm/W while achieving good color rendering."

The key to the improvement in light efficiency is the combination of new processes in film and UX:3 chip technology with new processes of conversion. Through the integration of expertise in all aspects of the production process, including epitaxial growth, thin-film chip architecture, conversion process and packaging technology, Osram Opto Semiconductors' R&D engineers have benefited a lot.