Phase‐Engineered Synthesis of Ultrathin Hexagonal and Monoclinic GaTe Flakes and Phase Transition Study

Abstract

GaTe is an important III-VI semiconductor with direct bandgap; thus, it holds great potential in the field of optoelectronics. Although it is known that GaTe can exist both in monoclinic and hexagonal phases, current studies are still exclusively restricted to the monoclinic phase of two dimensional (2D) GaTe owing to the difficulty in the fabrication of 2D hexagonal GaTe. Both monoclinic and hexagonal GaTe are demonstrated in this work, which can be selectively synthesized via a physical vapor deposition method, under precisely controlled growth temperatures. The pristine Raman and non-linear optical properties of hexagonal GaTe has been systematically explored for the first time; moreover, a novel selected-area phase transition from hexagonal to monoclinic of GeTe has been achieved via fs-laser irradiation. This work may pave the way for widely use of 2D GaTe in various fields in future.a strategy for selected-area phase transition from h-GaTe to m-GaTe, which may pave the way for wide applications of GaTe in future.

Molecular Beam Epitaxy of Layered Group III Metal Chalcogenides on GaAs(001) Substrates

“…However, under appropriate growth conditions, thick hexagonal GaTe flakes can be also obtained. Yu et al recently demonstrated the phase-controlled synthesis of monoclinic and hexagonal GaTe using conventional physical vapor deposition technique [ 112 ]. They found that growth temperature is the key factor for phase control of GaTe flakes, and h-GaTe flakes are intended to be stable under relatively low deposition temperature.…”

Space‐Confined Growth of 2D InI Showing High Sensitivity in Photodetection

“…Vapor deposition synthesis has been proven to be one of the most reliable methods in achieving high quality crystalline 2D materials. [ 24–26 ] In this study, a spaced‐confine PVD technique is applied to grow ultrathin InI. The deposition process is made up of an upstream in which a low melting point InI granule (351 °C) was put in, and a downstream zone where clean fluorophlogopite mica ([KMg 3 (AlSi 3 O 10 )F 2 ]) is arranged on a u‐shape glass tube (Figure S1, Supporting Information).…”

Lattice Dynamics and Thermodynamic Properties of Bulk Phases and Monolayers of GaTe and InTe: A Comparison from First‐Principles Calculations

“…Few‐layer GaTe flakes and thin films have been obtained experimentally since the late 90′s, [40] but have been studied most intensively in the past few years [41–46] . Many technics can be used for the synthesis of nano‐sized objects.…”

“…Generally, the initially acquired hexagonal thin films turn into monoclinic structures upon annealing at 500–700 °C, depending on their thickness. In this regard, the formation temperature may be the main factor for the phase control of GaTe films [45] …”

“…Few-layer GaTe flakes and thin films have been obtained experimentally since the late 90's, [40] but have been studied most intensively in the past few years. [41][42][43][44][45][46] Many technics can be used for the synthesis of nano-sized objects. Among them can be mentioned the liquid or mechanical exfoliation of powder or single-crystal GaTe, [41,42] chemical vapor deposition (CVD), [40] or physical vapor deposition (PVD), [45] and the molecular beam epitaxy.…”