Switching phenomenon in TlGaSe2 layered semiconductor

The Franz–Keldysh effect in the optical absorption spectrum of a TlGaSe2 layered semiconductor caused by charged native defects

“…Memristive (resistive-switching) memory effects have been recently observed by authors in nominally undoped bulk TlGaSe 2 samples [32,33]. Diode-type nonlinear currentvoltage characteristics in metal-TlGaSe 2 -metal structures have been revealed.…”

“…Electronically, undoped TlGaSe 2 samples have extremely high resistivity (low carrier density) in the dark, even at room temperature [31,33,[60][61][62]. It is presently accepted that the self-compensation of native deep-level acceptor states in TlGaSe 2 with intrinsic shallow donors is responsible for the low carrier density and poor electrical conductivity of this material [31].…”

“…In these structures, the rectification direction depends only on the polarity of previously applied bias to the electrodes and is independent of the electrode materials. This phenomenon has been understood within the framework of electromigration of charged entities (native Se vacancies or Se ions) leading to the formation of a thin insulator layer near the biased TlGaSe 2 sample surface [32,33].…”

A Study of Thermoelectric Performance of TlGaSe2 Layered Dichalcogenides from First‐Principles Calculations: Vacancy Defects Modeling and Engineering

“…At room temperature the electronic transport mechanism in the direction parallel to the layers is directly related to the presence of localized states in the bandgap created by native structural defects. [ 7–19 ] The electrical conduction perpendicular to the layers is expected to be highly sensitive to inevitable structural defects such as: planar defects presented between the layers due to a slipping of successive layers, point defects, charged impurities, deep level traps, dislocations as well as to many other crystal lattice imperfections that are mainly attributed to the interlayer stacking faults. [ 20–22 ] Only at extremely high temperatures, due to the thermally activated free carriers from the valence band the intrinsic electrical conduction is determined by a band‐to‐band mechanism.…”

Enhanced excitonic photoconductivity due to built-in internal electric field in TlGaSe2 layered semiconductor

“…In a series of recent studies, [5][6][7] we have discovered the presence of a built-in internal electric field in TlGaSe 2 single crystals, which significantly changes the electronic transport properties of this material. The built-in internal electric field is pumped into the TlGaSe 2 by cooling the crystal from room temperature down to 77 K under the existence of an external electric field.…”