| The temperature dependence of light emission from GaAs quantum well diode structures is examined both theoretically and experimentally using three device configurations.; For the edge light emitting diode (ELED) configuration, the temperature dependence of light generation with device current is predicted using gain and spontaneous emission spectra derived from an electron-hole plasma model. As the ELED temperature is lowered at a fixed current, the peak gain increases and the spontaneous emission spectrum is narrowed due to Fermi statistics. The importance of gain saturation in predicting the output power versus current profiles at high current densities is demonstrated.; In modeling the surface-emitting LED (SLED), it is shown that the temperature dependence of the non-radiative carrier lifetime in the quantum well can be extracted from the low current density experimental data. The absolute lifetime values obtained are somewhat dependent on the type of valence band model used (parabolic versus mixed).; When the heat sink temperature of a diode laser (DL) is lowered, threshold current usually decreases mainly because the peak gain, at fixed current, increases. In addition, slope efficiency usually increases as temperature is lowered due to an increase in carrier injection efficiency into the quantum well and a decrease in mode loss. For certain quantum well DLs, it has been discovered that threshold current remains relatively constant and slope efficiency decreases as temperature is lowered from 150K to 85K. The cause is shown to be unusual behavior of the carrier injection efficiency. Possible reasons for this anomalous behavior are discussed. |
