Book Synopsis Intersubband Optical Absorption of Electrons in Double Parabolic Quantum Wells of AlxGa1−xAs/AlyGa1−yAs *Project Supported by the National Natural Science Foundation of China (Grant No. 61274098). by :
Download or read book Intersubband Optical Absorption of Electrons in Double Parabolic Quantum Wells of AlxGa1−xAs/AlyGa1−yAs *Project Supported by the National Natural Science Foundation of China (Grant No. 61274098). written by and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract : Some realizable structures of double parabolic quantum wells (DPQWs) consisting of Al x Ga1− x As/Al y Ga1− y As are constructed to discuss theoretically the optical absorption due to the intersubband transition of electrons for both symmetric and asymmetric cases with three energy levels of conduction bands. The electronic states in these structures are obtained using a finite element difference method. Based on a compact density matrix approach, the optical absorption induced by intersubband transition of electrons at room temperature is discussed. The results reveal that the peak positions and heights of intersubband optical absorption coefficients (IOACs) of DPQWs are sensitive to the barrier thickness, depending on Al component. Furthermore, external electric fields result in the decrease of peak, and play an important role in the blue shifts of absorption spectra due to electrons excited from ground state to the first and second excited states. It is found that the peaks of IOACs are smaller in asymmetric DPQWs than in symmetric ones. The results also indicate that the adjustable extent of incident photon energy for DPQW is larger than for a square one of a similar size. Our results are helpful in experiments and device fabrication.
