Abstract This paper calculates the wavelengths of the interband transitions as a function of the Al mole fraction of AlxGa1-xN bulk material. 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 Schr?dinger and Poisson equations self-consistently. The Al mole fraction of the AlyGa1-yN barrier changes from 0.30 to 0.46, meanwhile the width of the well changes from 2.9 nm to 2.2 nm, for maximal intersubband absorption in the window of the air (3 μm < $\lambda$ < 5 μm). 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.
Received: 04 March 2009
Revised: 16 March 2009
Accepted manuscript online:
PACS:
85.60.Gz
(Photodetectors (including infrared and CCD detectors))
Fund: Project supported by the National
Natural Science Foundation of China (Grant Nos 60806042,
10774001,60736033, 60890193 and 60628402), National Basic Research
Program of China (Grant Nos 2006CB604908 and 2006CB921607), and the
Research Fund for the Doctora
Cite this article:
Cen Long-Bin(岑龙斌), Shen Bo(沈波), Qin Zhi-Xin(秦志新), and Zhang Guo-Yi(张国义) Optimization of a solar-blind and middle infrared two-colour photodetector using GaN-based bulk material and quantum wells 2009 Chin. Phys. B 18 5366
Altmetric calculates a score based on the online attention an article receives. Each coloured thread in the circle represents a different type of online attention. The number in the centre is the Altmetric score. Social media and mainstream news media are the main sources that calculate the score. Reference managers such as Mendeley are also tracked but do not contribute to the score. Older articles often score higher because they have had more time to get noticed. To account for this, Altmetric has included the context data for other articles of a similar age.
