PHONON-ELECTRON INTERACTIONS IN THE 2-DIMENSIONAL ELECTRON-GAS IN INGAAS-INALAS MODULATION-DOPED FIELD-EFFECT TRANSISTOR STRUCTURES STUDIEDBY RAMAN-SCATTERING
Je. Maslar et al., PHONON-ELECTRON INTERACTIONS IN THE 2-DIMENSIONAL ELECTRON-GAS IN INGAAS-INALAS MODULATION-DOPED FIELD-EFFECT TRANSISTOR STRUCTURES STUDIEDBY RAMAN-SCATTERING, Applied physics letters, 63(14), 1993, pp. 1909-1911
Raman scattering by coupled longitudinal optic phonons and two-dimensi
onal electron gas electrons in In0.53Ga0.47As-In0.52Al0.48As delta-dop
ed heterostructures provides a powerful probe of electronic properties
in these In-based structures. The two highest frequency modes, of the
three coupled electron-phonon modes expected in this system, were obs
erved, with the highest frequency mode being identified in InGaAs-base
d systems. The large dispersion of this mode makes it a particularly s
ensitive probe for changes in such properties as carrier concentration
and subband energy. For structures with higher carrier concentrations
coupling of the longitudinal optic phonon to multiple electron inters
ubband transitions is resolved. These measurements are particularly us
eful for heavily doped structures for which room-temperature Hall meas
urements cannot distinguish channel electrons from those in parallel c
onduction paths.