We study the procedure of miniband formation in CaN/lAIN constant-total-effective-radius multi-shell quantum dots （CTER-MSQDs） by calculating the subband energies. We find a different behavior of the miniband widths...We study the procedure of miniband formation in CaN/lAIN constant-total-effective-radius multi-shell quantum dots （CTER-MSQDs） by calculating the subband energies. We find a different behavior of the miniband widths and miniband gaps when the number of wells changes. It is shown that with increasing the inner quantum dot radiusRin, the number of minigaps decreases; with increasing the outer quantum dot radius Rout, the number of minigaps increases. We show that in the CTER-MSQDs systems, two kinds of minigaps exist： in the type （i） ones, minigaps increase monotonically when the number of wells increases while in the type （ii） ones, with increasing the number of wells, some of minigaps create, increase, at a critical number of wells decrease and finally vanish. Thus tuning of the m/nigaps and miniband widths in the CTER-MSQDs systems by using the number of wells, inner and outer quantum dot radii Rin and Rout is now possible.展开更多
The optoelectronic performance of quantum cascade detectors(QCDs)is highly sensitive to the design of the energy level structure,leading to the inability of a single structure to achieve broad wavelength tuning.To add...The optoelectronic performance of quantum cascade detectors(QCDs)is highly sensitive to the design of the energy level structure,leading to the inability of a single structure to achieve broad wavelength tuning.To address this issue,we propose and demonstrate a modular concept for very long wave infrared(VLWIR)QCDs based on a miniband diagonal transition scheme.The modular design makes the wavelength tuning only need to be adjusted for the absorption quantum well module rather than for the whole active region.Theoretical simulation shows that the wavelength tuning range is 39.6 meV(~14–30μm).To prove the feasibility of the scheme,three samples with different absorption well widths were fabricated and characterized.At 10 K,the response wavelengths of the three QCDs are 14,16,and 18μm,respectively,corresponding to responsivities and detectivities exceeding 2 mA/W and 1×10^(10)Jones.展开更多
基金Supported by the Iranian Nanotechnology Initiative Councilthe Shahrood University of Technology
文摘We study the procedure of miniband formation in CaN/lAIN constant-total-effective-radius multi-shell quantum dots （CTER-MSQDs） by calculating the subband energies. We find a different behavior of the miniband widths and miniband gaps when the number of wells changes. It is shown that with increasing the inner quantum dot radiusRin, the number of minigaps decreases; with increasing the outer quantum dot radius Rout, the number of minigaps increases. We show that in the CTER-MSQDs systems, two kinds of minigaps exist： in the type （i） ones, minigaps increase monotonically when the number of wells increases while in the type （ii） ones, with increasing the number of wells, some of minigaps create, increase, at a critical number of wells decrease and finally vanish. Thus tuning of the m/nigaps and miniband widths in the CTER-MSQDs systems by using the number of wells, inner and outer quantum dot radii Rin and Rout is now possible.
基金supported by the National Natural Science Foundation of China(Nos.61835011,62335015,12393830,62222408,and 12274404)the Key Program of the Chinese Academy of Sciences(No.XDB43000000)the Youth Innovation Promotion Association of the Chinese Academy of Sciences(No.2022112)。
文摘The optoelectronic performance of quantum cascade detectors(QCDs)is highly sensitive to the design of the energy level structure,leading to the inability of a single structure to achieve broad wavelength tuning.To address this issue,we propose and demonstrate a modular concept for very long wave infrared(VLWIR)QCDs based on a miniband diagonal transition scheme.The modular design makes the wavelength tuning only need to be adjusted for the absorption quantum well module rather than for the whole active region.Theoretical simulation shows that the wavelength tuning range is 39.6 meV(~14–30μm).To prove the feasibility of the scheme,three samples with different absorption well widths were fabricated and characterized.At 10 K,the response wavelengths of the three QCDs are 14,16,and 18μm,respectively,corresponding to responsivities and detectivities exceeding 2 mA/W and 1×10^(10)Jones.
