摘要
This paper calculates the wavelengths of the interband transitions as a function of the Al mole fraction of AlxGa1-xN bulk materml. It is finds that when the Al mole fraction is between 0.456 and 0.639, the wavelengths correspond to the solar-blind (250 nm to 280 nm). The influence of the structure parameters of AlyGa1-yN/GaN quantum wells on the wavelength and absorption coefficient of intersubband transitions has been investigated by solving the SchrSdinger and Poisson equations self-consistently. The Al mole fraction of the AlyGa1-yN barrier changes from 0.30 to 0.46, meanwhile the w;dth of the well changes from 2.9 nm to 2.2 am, for maximal intersubband absorption in the window of the air (3μm 〈 A 〈 5μm). The absorption coefficient of the intersubband transition between the ground state and the first excited state decreases with the increase of the wavelength. The results are finally used to discuss the prospects of GaN-based bulk material and quantum wells for a solar-blind and middle infrared two-colour photodetector.
This paper calculates the wavelengths of the interband transitions as a function of the Al mole fraction of AlxGa1-xN bulk materml. It is finds that when the Al mole fraction is between 0.456 and 0.639, the wavelengths correspond to the solar-blind (250 nm to 280 nm). The influence of the structure parameters of AlyGa1-yN/GaN quantum wells on the wavelength and absorption coefficient of intersubband transitions has been investigated by solving the SchrSdinger and Poisson equations self-consistently. The Al mole fraction of the AlyGa1-yN barrier changes from 0.30 to 0.46, meanwhile the w;dth of the well changes from 2.9 nm to 2.2 am, for maximal intersubband absorption in the window of the air (3μm 〈 A 〈 5μm). The absorption coefficient of the intersubband transition between the ground state and the first excited state decreases with the increase of the wavelength. The results are finally used to discuss the prospects of GaN-based bulk material and quantum wells for a solar-blind and middle infrared two-colour photodetector.
基金
Project supported by the National Natural Science Foundation of China (Grant Nos 60806042,10774001,60736033,60890193 and60628402)
National Basic Research Program of China (Grant Nos 2006CB604908 and 2006CB921607)
the Research Fundfor the Doctoral Program of Higher Education of China (Grant Nos 200800011021 and 20060001018)