Hydrostatic pressure and electric-field effects on the electronic and optical properties of InAs spherical layer quantum dot

External Parameters Affecting on the Photoluminescence of InAs Spherical Layer Quantum Dot

“…From the figure we see that with increasing the electric field component e z there was a red-shift in photoluminescence peak energy (wave length increase) which can be explained according to [12] [13] were the ground states energy go down with increasing the electric field due to lowering of the bottom of the well. In addition to that we see that the intensity of EL spectra decrease with increasing the applied electric field which may be attributed to the decrease in energy of the electron which proportional to the second power degree of the electric field [13] [16] [17]. Also we see that the quantum numbers (n c , l c , m c ) have a significant effects on photoluminescence peak energy at fixed value of applied electric field (e z ) which can be explained as Ref [10] where the authors concluded that to have more than one excitons by dots the probability must be considered, and must include other factors as relaxation time, radiative recombination rate, scattering, and others.…”

“…The opposite picture appears for photoluminescence peak energy Figure 1 (right) where there was a blue-shift in photoluminescence peak energy with increasing pressure at fixed value of temperature (T = 4 K) which may be attributed to the energy dependencies on the applied pressure, where a change in the energy gap of InAs as a result of changing the applied pressure will exist lead to changing the Coulomb interaction energy as a result of an internal huge strain of the dot of InAs, which will change the electrons and holes quantization energies [12]. In addition to that Ref [13] showed that the interband emission energy increases when the hydrostatic pressure increases. From the figure we see that with increasing the electric field component e z there was a red-shift in photoluminescence peak energy (wave length increase) which can be explained according to [12] [13] were the ground states energy go down with increasing the electric field due to lowering of the bottom of the well.…”