The influence of the polarization-induced electric field and other parameters on the subband structure in AlxGa1-x N /GaN coupled double quantum wells （DQWs） has been studied by solving the Schrodinger and Poisson e...The influence of the polarization-induced electric field and other parameters on the subband structure in AlxGa1-x N /GaN coupled double quantum wells （DQWs） has been studied by solving the Schrodinger and Poisson equations self-consistently. It is found that the polarization effect leads to an asymmetric potential profile of AlxGa1-xN/GaN DQ, Ws although the two wells have the same width and depth. The polarization effect also leads to a very large Stark shift between the odd and the even order subband levels that can reach 0.54eV. Due to the polarization-induced Stark shift, the wavelength of the intersubband transition between the first odd order and the second even order subband levels becomes smaller, which is useful for realization of optoelectronic devices operating within the telecommunication window region.展开更多
A variational method is adopted to investigate the properties of shallow impurity states near the interface in a free strained wurtzite GaN/AlxGa1-xN heterojunction under hydrostatic pressure and external electric fie...A variational method is adopted to investigate the properties of shallow impurity states near the interface in a free strained wurtzite GaN/AlxGa1-xN heterojunction under hydrostatic pressure and external electric field by using a simplified coherent potential approximation. Considering the biaxial strain due to lattice mismatch or epitaxial growth and the uniaxial strains effects, we investigated the Stark energy shift led by an external electric field for impurity states as functions of pressure as well as the impurity position, A1 component and areal electron density. The numerical result shows that the binding energy near linearly increases with pressure from 0 to 10 GPa. It is also found that the binding energy as a function of the electric field perpendicular to the interface shows an un-linear red shift or a blue shift for different impurity positions. The effect of increasing x on blue shift is more significant than that on the red shift for the impurity in the channel near the interface. The pressure influence on the Stark shift is more obvious with increase of electric field and the distance between an impurity and the interface. The increase of pressure decreases the blue shift but increases the red shift.展开更多
基金Supported by the National Natural Science Foundation of China under Grant Nos 60325413 and 60444007, the Cultivation Fund of the Key Scientific and Technical Innovation Project of the Ministry of Education of China under Grant No 705002,and the Beijing Natural Science Foundation of China under Grant No 4062017.
文摘The influence of the polarization-induced electric field and other parameters on the subband structure in AlxGa1-x N /GaN coupled double quantum wells （DQWs） has been studied by solving the Schrodinger and Poisson equations self-consistently. It is found that the polarization effect leads to an asymmetric potential profile of AlxGa1-xN/GaN DQ, Ws although the two wells have the same width and depth. The polarization effect also leads to a very large Stark shift between the odd and the even order subband levels that can reach 0.54eV. Due to the polarization-induced Stark shift, the wavelength of the intersubband transition between the first odd order and the second even order subband levels becomes smaller, which is useful for realization of optoelectronic devices operating within the telecommunication window region.
基金Project supported by the National Natural Science Foundation of China (Grant No 60566002)
文摘A variational method is adopted to investigate the properties of shallow impurity states near the interface in a free strained wurtzite GaN/AlxGa1-xN heterojunction under hydrostatic pressure and external electric field by using a simplified coherent potential approximation. Considering the biaxial strain due to lattice mismatch or epitaxial growth and the uniaxial strains effects, we investigated the Stark energy shift led by an external electric field for impurity states as functions of pressure as well as the impurity position, A1 component and areal electron density. The numerical result shows that the binding energy near linearly increases with pressure from 0 to 10 GPa. It is also found that the binding energy as a function of the electric field perpendicular to the interface shows an un-linear red shift or a blue shift for different impurity positions. The effect of increasing x on blue shift is more significant than that on the red shift for the impurity in the channel near the interface. The pressure influence on the Stark shift is more obvious with increase of electric field and the distance between an impurity and the interface. The increase of pressure decreases the blue shift but increases the red shift.
