Intervalley Electron Scattering

GaAs conduction band minimum is at

Secondary minimum of conduction band is at L (<111>)

L valley is sparsely populated at room temperature.

With E field, valley electrons gain energy between scattering events. If valley electron gain energy intervalley transfer becomes possible and the population at L valley becomes enhanced at the expense of valley.

At center of the valley . At L valley . Effective mass increases in L valley mobility and Drift velocity decreases in L valley as .

Lower valley mobility population ; upper valley mobility total electron

Arrange

is strong function of E.

is strong function of E.

for