Modeling source–drain voltage-dependent energy needed for emission or absorption of a photon in GaN devices

Based on the three-dimensional Schrödinger equation and hot-carrier effects, a physical model to clarify how the source–drain voltage affects the energy needed for the emission or absorption of a photon in GaN heterojunctions is proposed. The proposed model predicts that the energy needed for the emission or absorption of a photon in GaN heterojunctions will be linearly reduced by the square of the source–drain voltage and the device temperature. Thus, they will shift the emission or absorption spectrum of emission or absorption. The results of voltage and temperature-dependent spectrum noted in the Raman and photoluminescence experiments support the predicted results by the proposed model. Additionally, temperature-dependent spectral broadening observed in experiments can be described by the proposed model. It suggests that quantum coupling should be considered in GaN devices because of the hot-carrier effects, which denote that the energy of channel electrons can be very high. It is also essential for accurately measuring temperature by Raman measurement.