Electronic properties and phase transitions in low-dimensional semiconductors

Panich, A.M. (Dept. of Phys., Ben-Gurion Univ. of the Negev, Beer Sheva, Israel)

Source: Journal of Physics: Condensed Matter, v 20, n 29, 23 July 2008, 293202 (42 pp.)

Publisher: IOP Publishing Ltd., UK

Abstract: We present the first review of the current state of the literature on electronic properties and phase transitions in TlX and TlMX 2 (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, nonlinear 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. The 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. (305 refs.)

terms:  band structure  -  crystal structure  -  ferroelectric transitions  -  gallium compounds  -  hopping conduction  -  photoconducting materials  -  photoconductivity  -  semiconductor-metal boundaries  -  solid-state phase transformations  -  ternary semiconductors  -  thallium compounds