Bandgap Engineering of InSe Single Crystals through S Substitution

Abstract

Bandgap engineering offers opportunities for tailoring the properties of semiconductor materials for desired applications in microelectronics and optoelectronics. Alloys of different semiconductor materials can lead to the continuously tuning of the bandgap. Here, we report the bandgap engineering in layered InSe single crystals by substituting the Se atoms with S atoms. The formation of InS x Se 1−x single crystal alloy with x ≤ 0.3 is evidenced by the X-ray diffraction and resonant Raman spectra. The photoluminescence (PL) spectra peak position blue shifts from ∼1.27 to ∼1.42 eV as S composition increases from 0 to 0.3 in the alloys, which is consistent with the bandgap shifts calculated by density functional theory. Temperature dependence of the PL spectra indicate that the presence of S atoms decreases the strength of the electron−phonon interaction but increases the average phonon energy in InS x Se 1−x alloys. Our findings will open an intriguing avenue in understanding the fundamental physics in the III−VI layered semiconductor materials and their potential applications in optoelectronic devices.

Recent Advances in Quantum Effects of 2D Materials

“…Semimetal chalcogenides, such as InSe and GaSe, are a group of layered materials similar to TMDs . Recently, the widely researched semiconducting InSe is in its γ phase with a rhombohedral structure .…”

Theoretical study of Raman scattering in MoS2xSe2(1 − x) layered alloys

“…[1,6,8] TMD alloys consisting of different kinds of chalcogens (MXX', where X and X' are different chalcogens) have been successfully synthesized. [14][15][16] By introducing an additional doped chalcogen, the interactions in TMD alloys are significantly modulated, allowing engineering of their band structures and further enabling observation of many interesting phenomena. [14] As known, TMD alloys belong to the so-called general class ternary alloys (or pseudo-binary alloys), A 1 − x B x C, where x represents the fraction of substitutional B atoms in the cation sublattice.…”

“…[14][15][16] By introducing an additional doped chalcogen, the interactions in TMD alloys are significantly modulated, allowing engineering of their band structures and further enabling observation of many interesting phenomena. [14] As known, TMD alloys belong to the so-called general class ternary alloys (or pseudo-binary alloys), A 1 − x B x C, where x represents the fraction of substitutional B atoms in the cation sublattice. Similarly, AC 1 − y D y represents an anion-substituted alloy.…”

Reduced Bipolar Conduction in Bandgap-Engineered n-Type Cu0.008Bi2(Te,Se)3 by Sulfur Doping

“…However, a small amount of S doping in a Bi 2 (Te,Se) 3 n-type alloy would maintain its original crystal structure and would modify its electronic structure [9]. Typically, the E g values of the series of tellurides, selenides, and sulfides with identical cations increase with the size of the anion [10][11][12]. Therefore, the E g widening can be anticipated in S-doped Bi 2 (Te,Se) 3 alloys.…”