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研究了调制掺杂AlxGa1-xN GaN异质结中与二维电子气 (2DEG)有关的光致发光 ,发现温度 40K时Al0 .2 2 Ga0 .78N GaN异质结中 2DEG与光激发空穴复合形成的发光峰位于 3.448eV ,低于GaN自由激子峰 45meV。由于AlxGa1-xN GaN界面极强的压电极化场的影响 ,光激发空穴很快扩散进GaN平带区 ,导致 2DEG与光激发空穴复合几率很低。在GaN中接近Al0 .2 2 Ga0 .78N GaN界面处插入Al0 .12 Ga0 .88N限制层用于抑制光激发空穴的扩散 ,从而大大增强了 2DEG发光峰的强度。还研究了 2DEG发光峰随温度和光激发强度的变化。
The photoluminescence (2DEG) related to two-dimensional electron gas (2DEG) in a doped AlxGa1-xN GaN heterojunction was investigated. It was found that 2DEG and photoexcited hole recombination in the Al0.22Ga0.78N GaN heterostructure at 40K The resulting luminescence peak is located at 3.448 eV, 45 meV below the GaN free exciton peak. Due to the strong piezoelectric polarization field in the AlxGa1-xN GaN interface, photo-excited holes diffuse into the GaN flat zone very quickly, resulting in a low probability of 2DEG recombination with photoexcited holes. The insertion of an Al0.12 Ga0.88N confinement layer near the Al0.22Ga0.78N GaN interface in GaN suppresses the diffusion of photoexcited holes, thereby greatly enhancing the intensity of the 2DEG luminescence peak. The 2DEG luminescence peak was also studied as a function of temperature and photoexcitation intensity.