Optical absorption in Hg Te

Abstract

Optical absorption in intrinsic HgTe is measured in the wavelength range 2.0 to 25 pm at temperatures from 10 to 295 K. The rs 4 Fa transitions are observed a t low temperatures. The absorption coefficient is theoretically calculated using Kane's formulae for inverted band structure. The results of the calculations based both on the complete Kane theory and on the approximation of large spin-orbit splitting are obtained. It is shown that the latter approximation does not describe well experimental absorption data. The agreement between the experimental results and the theoretical curves which are based on the complete Kane theory with the reasonable values of band structure parameters is much better. However, for energies greater than 0.35 eV small discrepancy is observed. This discrepancy increases with the energy.Im Temperaturbereich von 10 bis 295 K wird die optische Absorption im intrinsischen Hg Te im Wellenliingenbereich von 2,O bis 25 pm gemessen. Die rs -I',-ubergiinge werden bei tiefen Temperaturen beobachtet. Der Absorptionskoeffizient wird mit der Kaneschen Formel fiir invertierte Bandstruktur theoretisch berechnet. Es werden Ergebnisse erhalten, die sowohl auf der vollstiindigen Kaneschen Theorie als auch auf der Naherung groBer Spit-Bahn-Wechselwirkung beruhen. Es wird gezeigt, daJ3 die letztere Niiherung die experimentellen Absorptionswerte nicht gut beschreibt. Die Vbereinstiqmung zwischen den experimentellen Ergebnissen und den theoretischen Kurven, die auf der vollstiindigen Kaneschen Theorie mit verniinftigen Werten fur die Bandstrukturparameter beruhen, ist vie1 besser. Jedoch werden fur Energien grol3er als 0,35 eV kleine Abweichungen beobachtet. Diese Abweichung wachst mit der Energie.

Plasma reflection and hole optical effective mass in p‐HgTe

“…However, in the investigated samples kpp/lE,J M 1, so to process the experimental data it is necessary to use the correction in the form (18). Substituting the sum of (7), (18) in (9) The resulting dependence ms,,(Nv) (curve 1) with account of &inter(Nv) is shown in Fig. 3 together with experimental points for T = 7 K .…”

“…I n Kane's model the exchange correction to the hole spectrum has the more complicated form [28] For hy <IEJ this exchange correction coincides with the second term of the righthand side of (14). However, in the investigated samples kpp/lE,J M 1, so to process the experimental data it is necessary to use the correction in the form (18). Substituting the sum of (7), (18) in (9) and taking into account the interband polarization by analogy with the previous one, we have the working formula where and ms,, is determined by (11).…”

“…However, in the investigated samples kpp/lE,J M 1, so to process the experimental data it is necessary to use the correction in the form (18). Substituting the sum of (7), (18) in (9) and taking into account the interband polarization by analogy with the previous one, we have the working formula where and ms,, is determined by (11). Using (Table 3, line 11).…”

“…obtained in the limits of the Kane model and the self-consistent field approximation. The latter will be easy to determine if together with the energy spectrum for electrons, and interband matrix element of the narrow-gap interaction [17], we use the spherical averaging of corrugation [18] in the energy spectrum for holes, which is determined by the first-order pertubation for kp interaction. I n the expressions given above…”

Mercury Cadmium Telluride (Hg1-xCdxTe)

“…Values calculated using Eq. [27] were digitized, and the k values calculated are displayed in Table VIII; a constant value of 3.74 was assumed for n in calculating the absorption coefficient from the measured reflection and transmission spectra. Absorption measurements for HgTe, the endpoint binary, which is semimetallic with a band gap of ----0.3 eV, have been reported by Szuszkiewicz [27] in the 0.05-0.625 eV region.…”