Electronic properties and phase transitions in low-dimensional semiconductors

TL;DR

This review discusses the electronic properties, phase transitions, and potential optoelectronic applications of low-dimensional TlX and TlMX2 semiconductors, highlighting their anisotropic behavior and various phase phenomena.

Contribution

It provides the first comprehensive review of the structural, electronic, and phase transition properties of TlX and TlMX2 compounds, integrating experimental and theoretical insights.

Findings

High anisotropy in electronic properties

Observation of semiconductor-metal phase transitions under pressure

Presence of temperature-induced structural phase transitions

Abstract

We present the first review of the current state of the literature on electronic properties and phase transitions in TlX and TlMX2 (M = Ga, In; X = Se, S, Te) compounds. These chalcogenides belong to a family of the low-dimensional semiconductors possessing chain or layered structure. They are of significant interest because of their highly anisotropic properties, semi- and photoconductivity, non-linear effects in their I-V characteristics (including a region of negative differential resistance), switching and memory effects, second harmonic optical generation, relaxor behavior and potential applications for optoelectronic devices. We review the crystal structure of TlX and TlMX2 compounds, their transport properties under ambient conditions, experimental and theoretical studies of the electronic structure, transport properties and semiconductor-metal phase transitions under high pressure, and sequences of temperature-induced structural phase transitions with intermediate incommensurate states. Electronic nature of the ferroelectric phase transitions in the above-mentioned compounds, as well as relaxor behavior, nanodomains and possible occurrence of quantum dots in doped and irradiated crystals is discussed.