A new method for improving LED luminous efficiency under low pressure

According to U.S. media reported recently, researchers at the Massachusetts Institute of Technology through a socket conversion device makes the light emitting diode (LED) to release more power than the light power consumption, power conversion efficiency can reach above 100%.

LED luminous principle is to convert electrical energy into light. At present, the design of a bright and efficient LED lamp is one of the biggest obstacles, is to increase the output power of the LED lamp instead of its efficiency decreased. The researchers at the Massachusetts Institute of Technology explained that their results greatly reduced the voltage applied. According to the calculation, when the voltage is reduced to half, the input power is reduced by 4 times, and the emitted optical power is consistent with the voltage, also reached half. In other words, the LED emission rate increases when the output power decreases.

In the experiment, the researchers reduced the input power of LED, only 30 picowatts, light measurement to the output reached 69 picowatts, efficiency up to 230%. The same physical mechanism can be applied to any LED. Under the external applied voltage, electrons and holes have a certain probability to produce photons. The researchers did not attempt to increase this probability, as in other studies, but to generate more power by using a small amount of heat generated by the vibrations of the atoms in the device.

This process of using the waste heat to make the LED a little cooler, the operation is similar to a thermoelectric cooler. Although cooling at room temperature is not sufficient to provide a practical temperature, it may be used to design a lamp that does not produce heat. When used as a heat pump, the device can be used for solid state cooling applications, even for generator equipment.

In theory, the low voltage strategy can produce any efficient photons at low voltages, and the researchers hope it will provide a new way to test the energy saving electromagnetic wave. Although this method is interesting in science, it will not immediately cause the commercialization of super efficiency LED, because the demonstration project can only produce a small amount of light with very low input power.