Optical spectra and energy band structure of layer‐type A^IVB^VI compounds

Abstract

The electroreflectance and absorption spectra as well as the hydrostatic pressure dependence of the fundamental absorption edge of GeS, GeSe, SnS, and SnSe crystals are investigated in polarized light. The lowest direct energy gaps are found to be 1V1— 1V1 (E | | a) and 1Λ4— 1Λ4 (E || b) for Ge and Sn monochalcogenides, respectively. The pressure coefficient of the energy gap 1Λ4— 1Λ4 dE/AP = = — (1.3 ± 0.1) × 10−4 eV/MPa of SnSe and SnS is almost twice larger than that of the gap 1V1— 1V1 in GeSe, GeS, and SnSe. On the basis of these investigations, different absorption mechanisms responsible for the fundamental absorption edge are discussed.

Optimization of parameters of chemical spray pyrolysis technique to get n and p-type layers of SnS

“…Electronic structure and structural calculations of SnS were deduced from photoelectron spectra by Ettema et al [13]. Optoelectronic properties suitable for the device fabrication were also reported by several groups [3][4][5][6][7].…”

“…It is a IV-VI layered compound semiconductor with distorted NaCl type orthorhombic crystal structure [3]. Due to its interesting structural, optical and electrical properties, SnS has become an important material for optoelectronics and photovoltaics [4][5][6][7] with many promising technological applications [8,9]. Further, properties like high absorption coefficient [10], direct band gap in the range 1.2-1.5 eV and indirect band gap in the range 1.0-1.2 eV [7,11] make SnS a more viable material for photovoltaic applications.…”

Optoelectronic properties of single-layer, double-layer, and bulk tin sulfide: A theoretical study

“…These calculations, as well as the values of the linear compressibilities, suggest that strain affects the dimensions of the structure primarily via the interlayer spacing, 33 so in the following we consider only variation in the separation of layers with fixed atomic positions in each layer and fixed in-plane lattice parameters. Although the assumption of incompressible layers is not appropriate for high strains, 31,33 it allows us to make useful predictions for smaller strains.…”

“…13,[16][17][18][19][20] General strategies for tuning the properties of the material, also relevant to the fabrication of novel electronic devices, include the use of atomically thin compounds [21][22][23][24] and the application of mechanical strain. [25][26][27] SnS has been extensively investigated in its bulk form [28][29][30][31][32][33][34] but few-layer and single-layer structures remain largely unexplored. 8,35 The measured properties of SnS samples depend on the synthesis route.…”

Preparation of SnS films by low temperature sulfurization

“…Furthermore, the alloys are costly: In and Ga are rare metals. In stark contrast, binary IV-VI orthorhombic semiconductor tin sulfide (SnS) [1] is a promising candidate as a light-absorbing medium of next-generation solar cells because SnS has direct bandgap energies of 1.3 eV [2] and a high absorption coefficient of 10 5 cm −1 [3]. Moreover, Sn and S are cheaper elements than those comprising CdTe and CIGS.…”