Microfluidic cooling of semiconductor light emission diodes

Optical properties of GaN-based light emission diode (LED) cooled with microfluidics have been studied as a function of injection currents at different water flow rates. Without cooling, the quantum efficiency of the LED emission degrades for large injection currents because of the limited heat dissipation. With microfluidic cooling, the maximum achievable injection current and the maximum light emission intensity increase with the water flow rate. Correspondingly, the red-shifts of the emission peaks are reduced in the whole range of the injection currents when the LED is cooled. Such a simple technique should also be applicable to other types of LEDs or high density LED arrays.