Inversion of the Γ and L conduction bands of GaSb under uniaxial stress

Abstract

With photoluminescence experiments under high uniaxial stress in (11 1) crystallographic dmction it is possible to observe the inversion of the I? and L conduction bands of GaSb directly in the spectra a t 6.5 kbar. From the line shifts the uniaxial deformation potential constant of the L conduction band E, = (15 f 1) eV is determined. Also the energy separation between the two conduction bands at zero stress is obtained from the experimental data: AE = (93 f 3) meV.A donor level assosiated with the L conduction band is seen in the spectra at higher stresses. The ionisation energy of this donor is determined to El = 33 meV.

Conduction-band crossover induced by misfit strain inInSb∕GaSbself-assembled quantum dots

“…5,7 Hence, one can expect the most prominent ⌫-L crossover to be observed in SAQD heterostructures with GaSb as a matrix material. In fact, the ⌫-L crossover has been observed in bulk GaSb under uniaxial stress along the ͗111͘ direction.…”

“…In fact, the ⌫-L crossover has been observed in bulk GaSb under uniaxial stress along the ͗111͘ direction. 7 This effect was mainly due to the L-valley splitting. It is illustrative to note that the required shear strain was as small as 0.25%, so the crossover effect ought to be expected in SAQD heterostructures.…”