AlxGa1-xN/GaN双量子阱的结构和掺杂浓度对子带间跃迁波长和吸收系数的影响

用薛定谔方程和泊松方程自洽计算的方法研究了Al_0.75Ga_0.25N/GaN对称双量子阱(DQWs)中子带间跃迁(ISBT)的波长和吸收系数对中间耦合势垒高度、中间耦合势垒宽度、势阱宽度和势垒掺杂浓度的依赖关系.研究发现，第一奇序子带S_1ood与第二偶序子带S_2even ISBT波长随着中间耦合势垒高度的降低而变短.当中间耦合势垒高度高于0.62 eV时，S_{1odd<关键词：自洽x}Ga_1-xN/GaN双量子阱')" href="#">Al_xGa_1-xN/GaN双量子阱子带间跃迁

Influence of structure and doping concentration of AlxGa1-xN/GaN double quantum wells on wavelength and absorption coefficient of intersubband transitions

By solving the Schrdinger and Poisson equations self-consistently, the central barrier height, central barrier width, well width, and doping concentration in the barriers of symmetric Al_0.75Ga_0.25N/GaN double quantum wells (DQWs) have been studied to investigate their influences on the wavelength and absorption coefficient of intersubband transitions (ISBTs). A smaller wavelength of the ISBT between the first odd and the second even order subbands (S_1odd-S_2even ISBT) in Al_0.75Ga_0.25N/GaN DQWs and a larger absorption coefficient of the S_1odd-S_2even ISBT were obtained with decreased central barrier height, when the central barrier height was larger than 0.62 eV. The wavelength of the S_1odd-S_2even ISBT decreases, and the absorption coefficient of the S_1odd-S_2even ISBT increases, when the width of the central barrier is reduced. On the other hand, decreasing the width of the well will result in smaller wavelength of the S_1odd-S_2even ISBT and larger absorption coefficient of the S_1odd-S_2even ISBT when the width of the well is narrower than 1.9 nm. When doping concentration in the barriers is smaller than 10¹⁸/cm³， the wavelength of the S_1odd-S_2even ISBT is unchanged, while the absorption coefficient of the S_1odd-S_2even ISBT increases with the doping concentration. These results provide useful guidance for realization of ultrafast two-color optoelectronic devices operating in the optical communication wavelength range.