HELICONS AND NONRESONANT CYCLOTRON ABSORPTION IN SEMICONDUCTORS .I. INSB

We describe techniques of experiment and analysis for using microwave helicon interferometry and nonresonant cyclotron absorption to determine the carrier densities, effective masses, mobilities, and lattice dielectric constants for certain semiconductors and semimetals. InSb was used as an example and as a test of the applicability of our techniques. Circularly polarized microwaves of frequencies 24 and 70 GHz and magnetic fields up to 1.9 Wb/m2 were used in reflection and transmission experiments at temperatures between 1.3 °K and room temperature. The primary studies were made at 77 °K on single crystals of n-type InSb which ranged in electron concentration from 8×1019 to 7×1022m-3. For these samples we obtained m*=0.014m0 and εL=19.7ε0. Studies of the change in carrier concentration with temperature gave a value of 0.26 eV for the band gap. All of these numbers are in good agreement with literature values and confirm the utility of the techniques which were subsequently used to study gray tin and Hg1-xCdxTe. © 1969 The American Physical Society.