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Influence of Ch substitution on structural, electronic, and thermoelectric properties of layered oxychalcogenides (La0.5Bi0.5O)CuCh (Ch = S, Se, Te): A new insight from first principles
Muhammady S.a, Widita R.a, Darma Y.a
a Department of Physics, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Bandung, 40132, Indonesia
[vc_row][vc_column][vc_row_inner][vc_column_inner][vc_separator css=”.vc_custom_1624529070653{padding-top: 30px !important;padding-bottom: 30px !important;}”][/vc_column_inner][/vc_row_inner][vc_row_inner layout=”boxed”][vc_column_inner width=”3/4″ css=”.vc_custom_1624695412187{border-right-width: 1px !important;border-right-color: #dddddd !important;border-right-style: solid !important;border-radius: 1px !important;}”][vc_empty_space][megatron_heading title=”Abstract” size=”size-sm” text_align=”text-left”][vc_column_text]© The Royal Society of Chemistry.We study the structural, electronic, and thermoelectric properties of p-type layered oxychalcogenides (La0.5Bi0.5O)CuCh (Ch = S, Se, Te) from first principles. Ch substitution from S to Te enhances the local-symmetry distortions (LSDs) in CuCh4 and OLa2Bi2 tetrahedra, where the LSD in OLa2Bi2 is more pronounced. The LSD in CuCh4 tetrahedra comes from the possible pseudo-Jahn-Teller effect, indicated by the degeneracy-lifted t2g and eg states of Cu 3d10 orbital. The Ch substitution decreases bandgap from 0.529, 0.256 (Γ → 0.4Δ), to 0.094 eV (Z → 0.4Δ), for Ch = S, Se, Te, respectively, implying the increasing carrier concentration and electrical conductivity. The split-off energy at Z and Γ points are also increased by the substitution. The valence band shows deep O 2p states in the electron-confining [LaBiO2]2+ layers, which is essential for thermoelectricity. (La0.5Bi0.5O)CuTe provides the largest thermoelectric power from the Seebeck coefficient and the carriers concentration, which mainly come from Te 5px/py, Cu 3dzx, and Cu 3dzy states. The valence band shows the partial hybridization of t2g and Chp states, implied by the presence of nonbonding valence t2g states. This study provides new insights, which predict experimental results and are essential for novel functional device applications.[/vc_column_text][vc_empty_space][vc_separator css=”.vc_custom_1624528584150{padding-top: 25px !important;padding-bottom: 25px !important;}”][vc_empty_space][megatron_heading title=”Author keywords” size=”size-sm” text_align=”text-left”][vc_column_text]Electrical conductivity,First principles,Functional devices,Gamma point,Local symmetry,Oxychalcogenides,P-type,Thermoelectric properties[/vc_column_text][vc_empty_space][vc_separator css=”.vc_custom_1624528584150{padding-top: 25px !important;padding-bottom: 25px !important;}”][vc_empty_space][megatron_heading title=”Indexed keywords” size=”size-sm” text_align=”text-left”][vc_column_text][/vc_column_text][vc_empty_space][vc_separator css=”.vc_custom_1624528584150{padding-top: 25px !important;padding-bottom: 25px !important;}”][vc_empty_space][megatron_heading title=”Funding details” size=”size-sm” text_align=”text-left”][vc_column_text]This research was supported by the Ministry of Research and Technology (MORT)/The National Agency for Research and Innovation (NARI) of the Republic of Indonesia 2020 research program.[/vc_column_text][vc_empty_space][vc_separator css=”.vc_custom_1624528584150{padding-top: 25px !important;padding-bottom: 25px !important;}”][vc_empty_space][megatron_heading title=”DOI” size=”size-sm” text_align=”text-left”][vc_column_text]https://doi.org/10.1039/d0ra05187j[/vc_column_text][/vc_column_inner][vc_column_inner width=”1/4″][vc_column_text]Widget Plumx[/vc_column_text][/vc_column_inner][/vc_row_inner][/vc_column][/vc_row][vc_row][vc_column][vc_separator css=”.vc_custom_1624528584150{padding-top: 25px !important;padding-bottom: 25px !important;}”][/vc_column][/vc_row]