“…For these reasons, the signal level of terahertz emission, observed in the present study, was significantly lower, than in [2][3][4][5]. A special feature of our samples is also that they are the functional LED structures [8][9][10] and contain a number of components in addition to the InGaN/GaN layers. In this regard, we additionally checked, if the terahertz signal (for example, due to the optical rectification in GaN) is absent in some of the thin plates of n-and p-GaN and sapphire.…”