IEC 60747-5-8 Ed. 1.0 b:2019

IEC 60747-5-8:2019 specifies the terminology and the measuring methods of various efficiencies of single light emitting diode (LED) chips or packages without phosphor. White LEDs for lighting applications are out of the scope of this part of IEC 60747. The efficiencies whose measuring methods are defined in this part are the power efficiency (PE), the external quantum efficiency (EQE), the voltage efficiency (VE), and the light extraction efficiency (LEE). To measure the LEE, the measurement data of the internal quantum efficiency (IQE) is used, whose measuring method is discussed in IEC 60747-5-9 and IEC 60747-5-10. The injection efficiency (IE) and the radiative efficiency (RE) are given definitions only.