LED chip and component maker SemiLEDs Corp of Hsinchu Science Park, Taiwan has announced power improvements to its EV-LED family of products (launched last June), allowing single-chip emitters to achieve luminous efficiency of more than 130lm/W.
SemiLEDs says that recent improvements to both the epitaxial quality and chip process of its EV family of LED chips have allowed a 10% increase in blue chip brightness and an 8% reduction in forward voltage (Vf) in mass production. This can enable users to achieve luminous efficiency of more than 130lm/W (in a cool-white LED) and 110lm/W (in a warm-white LED). Measurements were taken at a drive current of 350mA.
SemiLEDs says that, with its Enhanced Vertical (EV) technology, it has been able to increase brightness and reduce defects through new advances in epitaxial and process technology. Production monitoring has shown an increase of 10% in brightness distribution and improved leakage current yield. The EV technology not only increased the luminous output but also enabled a down shift of the Vf distribution by 8%, increasing efficiency by 6-8% at 350mA.
SemiLEDs reckons that the improvements make its chips suitable for demanding directional applications such as street lighting, tunnel lighting and indoor retail lighting.
