The effect of temperature on the linear polarization of the photoluminescence of an ordered AlGaInP semiconductor alloy

The photoluminescence (PL) emission of atomically ordered III-V epitaxial alloys grown by MOVPE is frequently polarized. We analyze the linear polarization of the PL emission from the (001) surface of an epitaxial semiconductor quaternary AlGaInP alloy with high atomic ordering parameter. We measured and calculated the temperature dependence of the PL polarization for a wide temperature range (10-300 K). Comparing the measured polarization patterns with patterns calculated using constant values of the atomic ordering and elastic biaxial strain parameters, we found that the calculations do not predict correctly the PL polarization patterns at low temperature. Furthermore, our measurements show that at room temperature the measured and calculated PL polarization degrees are almost the same, while at low temperature the measured values are smaller than those predicted by the model used for the calculations. We discuss the factors that could cause this discrepancy and conclude that it can be attributed to the complex internal structure of the layer.