Berlin 2024 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 5: Optical Properties I

HL 5.2: Talk

Monday, March 18, 2024, 09:45–10:00, EW 561

Conduction band nonparabolicity, chemical potential, and carrier concentration of intrinsic InSb as a function of temperature — •Stefan Zollner, Carlos Armenta, and Sonam Yadav — New Mexico State University, Las Cruces, NM, USA

The goal of our work is to predict the complex dielectric function of intrinsic indium antimonide from 80 to 800 K, which was recently measured using spectroscopic ellipsometry [M. Rivero Arias et al., J. Vac. Sci. Technol. B 41, 022203 (2023)]. The first step is to find a good analytical description for the nonparabolic band structure of InSb based on k^→·p^→ theory. We implement a simple 8×8 k^→·p^→ Hamiltonian based on the work of Kane (1956) within the limit of large spin-orbit splittings, where a single nonparabolicity parameter provides a good description of the density of states. We select a value of the momentum matrix element P which yields the experimental effective electron mass for the unrenormalized low-temperature band gap. The temperature-dependence of the effective electron mass is then calculated taking into account only the thermal expansion contribution to the redshift of the direct band gap, not the renormalization due to deformation-potential electron phonon interactions. With this approach, we calculate the temperature dependence of the chemical potential, the thermal Burstein-Moss shift, and the carrier concentration of intrinsic InSb, which is in good agreement with electrical Hall effect measurements. The calculation of the temperature-dependent dielectric function will be the next step.

Keywords: Indium antimonide; Dielectric function; Spectroscopic ellipsometry; Chemical potential; Burstein-Moss shift