Infrared-to-violet tunable optical activity in atomic films of GaSe, InSe, and their heterostructures

//Infrared-to-violet tunable optical activity in atomic films of GaSe, InSe, and their heterostructures

Two-dimensional (2D) semiconductors—atomic layers of materials with covalent intra-layer bonding and weak (van der Waals or quadrupole) coupling between the layers—are a new class of materials with great potential for optoelectronic applications. Among those, a special position is now being taken by post-transition metal chalcogenides (PTMC), InSe and GaSe. It has recently been found (Bandurin et al 2017 Nat. Nanotechnol . 12 223–7) that the band gap in 2D crystals of InSe more than doubles in the monolayer compared to thick multilayer crystals, while the high mobility of conduction band electrons is promoted by their light in-plane mass. Here, we use Raman and PL measurements of encapsulated few layer samples, coupled with accurate atomic force and transmission electron microscope structural characterisation to reveal new optical properties of atomically thin GaSe preserved by hBN encapsulation. The band gaps we observe complement the spectral range provided…

Published in: "2DMaterials".

2018-09-25T12:33:45+00:00September 25th, 2018|Categories: Publications|Tags: , , |
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