Generation of microwave harmonics by non-ohmic surface layers in quantum wells of compound semiconductors at low lattice temperatures

Abstract

It is well known that the free electron ensemble in the material of a semiconductor structure, at times, may exhibit electrical nonlinearity, when an effectively large electric field is applied. Under the condition, when a microwave field is also superimposed at the input, the efficiency of generation of second harmonic has been estimated here, using the electrical nonlinearity of the surface layers in infinite triangular quantum wells of compound semiconductors at low lattice temperatures. The nonlinear electrical characteristics are obtainable in the widely used framework of the field-dependent effective electron temperature approximation. Some of the explicit low-temperature features, like the degeneracy of the ensemble, and their interaction with the piezoelectric phonons, are taken into account. The efficiency characteristics which are thus obtained for some practically used modulation doped heterostructures of compounds, like InSb, GaAs, and GaN, seem to be interesting. Moreover, the specific low-temperature features are found to effect significant changes in the efficiency characteristics of the layers of such compounds. How the present analysis leaves much scope for further refinement is also discussed.