Temperature dependence of the threshold electric field in a hot electron VCSEL

The operation of the hot electron light emitting and lasing in semiconductor heterostructure - vertical cavity surface emitting laser (HELLISH-VCSEL) devices is based on hot carrier transport parallel to the layers of Ga1-xAIxAs p-n junction. It is therefore a field-effect device and the light emission from the device is independent of the polarity of the applied voltage. The authors present a study of the temperature dependence of the operational characteristics of the device. Experimental studies comprise the measurements of the I-V characteristics, electroluminescence, reflectivity, and temperature-dependent light-applied electric field (L-F) characteristics. To obtain the optimum operation temperature, the gain calculations, reflectivity spectra, and band gap calculations were carried out at different temperatures. The temperature dependence of the threshold electric field is compared with the model calculations, where radiative transitions without momentum (k) selection are considered.