Theory and applications of band-aligned superlattices

Relaxation mechanisms of the photoelectrons in the second miniband of a superlattice structure

“…The extracted interminiband relaxation time from the fitting is 11 ps for our sample. This value is consistent with the intersubband relaxation time in the quantum-well infrared photodetectors which is in the range from several picoseconds to tens of picoseconds [14]- [18].…”

“…One photoelectron represented by wavefunction can generate carrier flux given by [14] (2) and the maximum value is 35 (5.8) times larger than the bottom (top) of the second miniband. The flux peak at 7.6 m does not appear in the experimental data of the responsivity.…”

Miniband formation in a quantum dot crystal

“…8 Other quantum dot synthesis techniques, such as electrochemical self-assembly, have also led to a high degree of lateral regimentation resulting in hexagonal quantum dot arrays. 9,10 In comparison to conventional quantum well superlattices 11 or multiple quantum well structures, 12 QDS that consists of multiple arrays of quantum dots may have many advantages in applications due to its modified density of electronic states and optical selection rules. For example, due to relaxed intraband optical selection rules in QDS, they are capable of absorbing normally incident radiation 3,4 while it is not possible in quantum well superlattices.…”

Joint Services Electronics Program: Electronics Research at the University of Texas at Austin

“…The shift of these transition energies under different electric fields is shown in Figure 9. The shift of bound state energies under electric field was calculated using the variational method of Bastard [31]. These results should prove to be useful in designing Si/Si l -x Ge x MQW structures for QCSE to be applicable in the technologically important wavelengths 1.3 and 1.55 micron.…”