Time-Resolved Electroluminescence Spectroscopy of a White Light Emitting Diode
One of the most powerful techniques to understand the behaviour and performance of electrical devices is electroluminescence spectroscopy. In electroluminescence (EL) spectroscopy a working device, such as a light emitting diode or solar cell, is placed inside a spectrometer and the light emission properties of the device studied. EL spectroscopy can be performed as either a steady state or time-resolved measurement. In steady state EL spectroscopy a constant current is applied to the device and the emission spectrum and intensity of the emitted light is measured. From this information, useful properties such as the optical bandgap and chromaticity coordinates can be calculated. In time-resolved or transient electroluminescence the temporal response of light emission from the device to short voltage pulses is measured which can be used to investigate the charge carrier dynamics inside the device. In this application note the FLS1000 Photoluminescence Spectrometer is used to investigate the emission properties of a phosphor coated indium gallium nitride white light LED using both steady state and time-resolved electroluminescence spectroscopy.
Figure 1: Time-resolved electroluminescence of white light InGaN LED. (a) EL decay measured at 450 nm and 575 nm using TCSPC. The EL decay at 575 nm was fit with a monoexpoential decay using Fluoracle, giving a lifetime of 65 ns. (b) Time-resolved electroluminescence emission spectrum measured using TCSPC.
Download the Electroluminescence Spectroscopy Application Note
FLS 1000 Photoluminescence Spectrometer
Sign-Up for our Application and Technical Notes
If you have enjoyed reading our Application Note, why not sign-up to our infrequent newsletter via our red Sign-up button below.