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RESEARCH PRODUCT
Pressure Dependence of the Low-Frequency Dielectric Constant in III-VI Semiconductors
V. MuñozDaniel ErrandoneaAlfredo SeguraA. Chevysubject
Phase transitionCondensed matter physicsChemistrybusiness.industryDielectricLow frequencyPressure dependenceCondensed Matter PhysicsCapacitanceElectronic Optical and Magnetic MaterialsSemiconductorPolarizabilityLattice (order)businessdescription
In this work we report on the pressure dependence of the low-frequency dielectric constant parallel to the c-axis (e∥) in GaS, GaSe, and InSe as obtained from direct capacitance measurements. A large increase of e∥ with pressure has been observed. The pressure change of the lattice polarizability along the c-axis is calculated in the framework of a rigid-ion model from the change of the angle of the anion–cation bond with respect to the layer plane, which results in a slight increase of the lattice contribution. Consequently, the pressure behaviour of e∥ is proposed to arise from the large increase of the electronic polarizability along the c-axis. This is explained through a decrease of the Penn gap, whose energy and pressure coefficients are shown to scale with those of the indirect gap in these compounds. A supplementary and reversible step-increase of e∥ has been observed at 1.6 GPa in GaS. This increase has been associated to a phase transition that was reported by other authors.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 1999-01-01 | physica status solidi (b) |