Improvement of LED Performance with an Integrated Thermoelectric Cooling Package

Abstract

The high junction temperature for a working light-emitting diode (LED) will lead to a decrease in luminous efficiency, redshift in wavelength, and shortened lifetime. Conventional cooling methods such as air cooling and water cooling cannot meet the heat dissipation requirements of highly integrated high-power LED cooling systems. A thermoelectric cooler (TEC) has the characteristics of small size, long life, light weight and high reliability, which can effectively reduce the operating temperature of an LED, obtain higher luminous efficiency and improve its service life. In this paper, LED cooling systems with integrated TEC packaging are studied by experiments. Through the comparison of RGBW LED, the influence of temperature on LED is observed, especially the optical characteristics such as spectrum, irradiance and CRI. By observing the board temperature and regulation of optical parameters, the optical characteristics of an LED with an integrated TEC thermal package are significantly improved. For RGB LEDs cooled by a TEC and large-sized heat sink, the wavelength of the red LED is restored by 5 nm. In the case of a white LED cooled by a TEC with a small-sized heat sink, the illuminance is increased by 3 times from 26,768.93 Lux to 82,962.79 Lux with TEC power increased from 0 W to 14.4 W. As an effective refrigeration device for LEDs, a TEC can supply an extra performance regulation method for realizing a controllable cooling environment. By integrating RGBW LEDs with a TEC, this study provides a solution for LED heat dissipation and studies TEC temperature control for the optical performance of LEDs to provide a basis for adjusting the optical performance of LEDs through a TEC.