First-principles calculations of monolayered Al₂Te₅: a promising 2D donor semiconductor with ultrahigh visible light harvesting

Abstract

Atomically thin two-dimensional (2D) crystals have piqued researchers' curiosity, due to their unique features and potential applications, such as catalysis and ion batteries. One essential and desirable aspect of 2D...

Polytelluride square planar chain-induced anharmonicity results in ultralow thermal conductivity and high thermoelectric efficiency in Al2Te5 monolayers

“…These compounds have been synthesized and exhibit stability at high temperatures. 47 Their low exfoliation energies, approximately 14.98 meV Å −2 , 48 align closely with that of MoS 2 (26.21 meV Å −2 ), 49 Bi 2 Te 3 (25 meV Å −2 ) 50 and Ca 2 N (68.03 meV Å −2 ), 51 suggesting potential for their 2D construction. Using comprehensive Density functional theory (DFT) calculations we find significant thermoelectric power factor (PF) and extremely low lattice thermal conductivity ( κ L ) in Al 2 Te 5 , a combination that leads to a zT exceeding unity at 600 K. Despite sharing a similar composition, these compounds display distinct molecular structures within their crystal lattices.…”

“…2 Phonon transport properties: (a) phonon dispersion and atom projected DOS of Al 2 Te 5 (top) and Al 2 Te 3 (bottom), (b) mode decomposed Gru ¨neisen parameter as a function of frequency for Al 2 Te 5 (top) and Al 2 Te 3 (bottom), (c) the square of group velocities multiplied by relaxation time (n 2 t) along the a-and b-axis, and (d) lattice thermal conductivities of Al 2 Te 5 (top) and Al 2 Te3(bottom) as a function of temperature from 300 to 900 K along the in-plane axis. Note that the melting temperature of Al 2 Te 5 is estimated to be between 800 K and 900 K based on ab initio molecular dynamics (AIMD) simulation 48.…”

Decoding the Atomic Structure of Ga2Te5 Pulsed Laser Deposition Films for Memory Applications Using Diffraction and First-Principles Simulations

“…In other words, a controlled crystallization of the amorphous Ga2Te5 PLD film yields a high-quality, stable tetragonal crystal promising for photovoltaic, thermoelectric, en- Even more surprisingly, gallium pentatelluride appears to be perfectly stable after 15 months at room temperature, Figure S1 (Supplementary Information), in contrast to bulk Ga 2 Te 5 , transforming into cubic Ga 2 Te 3 and trigonal tellurium within several weeks [30]. In other words, a controlled crystallization of the amorphous Ga 2 Te 5 PLD film yields a highquality, stable tetragonal crystal promising for photovoltaic, thermoelectric, energy storage, and memory applications [33][34][35][36][37]. On the contrary, the slow cooling or fast quenching of molten Ga 2 Te 5 gives a polycrystalline mixture of cubic gallium sesquitelluride and trigonal Te, Figure S1, fully consistent with the Ga-Te phase diagram, Figure 1d.…”

“…Consequently, the relationship between the amorphous material—obtained by the near instantaneous freezing of the highly excited fragments, particles, liquid globules, etc., existing in the laser-induced plasma (plume)—and a metastable crystal is expected to be complex, leaving room for various intermediate configurations and states. Deep insights into the atomic structure and associated electronic, optical, thermal, and other properties are a key for the rational design of next-generation PCMs and new functional materials for use in photovoltaic, thermoelectric, DNA sensing, and energy storage applications [ 33 , 34 , 35 , 36 , 37 ].…”

Theoretical design of a photodetector based on a two-dimensional SnSe2/GaP type-II heterostructure

“…However, graphene is somewhat limited in many optoelectronic applications due to its zero bandgap disadvantage. 5,6 Therefore, many scientists are focusing their attention on the search for new 2D materials, [7][8][9] including 2D transition metal sulphide compounds (TMDCs) (WS 2 , WSe 2 , MoTe 2 , and MoSe 2 ), [10][11][12][13] elemental alkenes of main group V (blue phosphorene, black phosphorene, and antimonene) [14][15][16][17][18] and 2D boron nitride. 19 2D materials have excellent properties and are considered by many scientists to be an alternative to graphene in semiconductor devices.…”