SBIR-STTR Award

Treatment of water with ultraviolet (UV) light, which destroys target DNA of microorganisms, is the safest, most reliable, and sustainable way of freeing water from microbial contamination. This process is desired in place of chlorination and is widely used in the US for wastewater treatment. We propose the development of a highly efficient UV LED with emission at 265 nm, with EQE>30%, and WPE>15% for water disinfection and surface sterilization applications. By using single crystal AlN substrates and proper point defect management, we will increase the performance of UV LEDs over the current state-of-the-art. Growth on such low dislocation density substrates increases the crystal quality in the doped layers and active region of the LED which results in superior wall plug efficiency and avoids degradation and poor operating lifetime typically observed in UV LEDs grown on sapphire and other non-native substrates.

Treatment of water with ultraviolet (UV) light, which destroys target DNA of microorganisms, is the safest, most reliable, and sustainable way of freeing water from microbial contamination. This process is desired in place of chlorination and is widely used in the US for wastewater treatment. We propose the development of a highly efficient UV LED with emission at 265 nm, with EQE>30%, and WPE>15% for water disinfection and surface sterilization applications. By using single crystal AlN substrates and proper point defect management, we will increase the performance of UV LEDs over the current state-of-the-art. Growth on such low dislocation density substrates increases the crystal quality in the doped layers and active region of the LED which results in superior wall plug efficiency and avoids degradation and poor operating lifetime typically observed in UV LEDs grown on sapphire and other non-native substrates. ---------- Based on the successful completion of the Phase II effort that demonstrated state-of-the-art UVC LEDs with emission around 265 nm and output power of 25 mW (unpackaged device), a continuation of this effort is proposed. The objectives of the sequential Phase II effort will focus on (a) improving the developed UVC LEDs in terms of efficiency and output power, (b) demonstration of novel packaging schemes that take advantage of the high thermal conductivity of AlN substrates with the goal to achieve unmatched current and optical power densities, and (c) establishing a packaged single chip UVC LED with > 150 mW output power and wall plug efficiency > 20%, (d) demonstration of multi-chip UVC LEDs with > 600 mW output power, and (e) integration of the developed LEDs with mobile water disinfection systems. By achieving these objectives, the Army and other DoD partners will be able to build a new class of low cost, durable, and deployable water purification systems that increase the safety and maintain readiness of its deployed personnel.