Thermal-induced tensile and compressive strain effects on the THz emission from epitaxially lifted-off undoped/n-type GaAs
We report on the temperature effects on the terahertz (THz) emission of undoped/n-type gallium arsenide (GaAs) thin films bonded onto silicon (Si), magnesium oxide (MgO), and acetate substrates. The THz emission was found to significantly decrease for compressively strained samples as compared to their as-grown counterpart. Supporting data from temperature-dependent photoluminescence spectroscopy showed that the films bonded onto acetate exhibit compressive strain similar to that of films bonded to MgO. This result was attributed to a compressive strain-induced electric field which reduced the total electric field.