IIARD International Institute of Academic Research and Development

INTERNATIONAL JOURNAL OF CHEMISTRY AND CHEMICAL PROCESSES (IJCCP )

E-I SSN 2545-5265
P- ISSN 2695-1916
VOL. 10 NO. 6 2024
DOI: 10.56201/ijccp.v10.no6.2024.pg40.50

---

Electronic Properties of Monoclinic and Tetragonal Phases of Copper Germanium Sulphude (Cu2ges3)

Nwogu, A. Q., Omehe N. N

---

Abstract

Cu?GeS? is a chalcopyrite-like structured material that can crystalize in different structural phases. Each phase exhibits distinct electronic properties due to variations in atomic arrangement and bonding characteristics. In this study, we investigated the electronic properties of the monoclinic and tetragonal phases of Cu?GeS? using first-principles calculations based on density functional theory (DFT+U). Precisely, the ALBINIT software was used to generate and analyse data. The outcome of this theoretical study showed that the monoclinic phase exhibit an indirect band gap and a calculated bandgap value of 1.2ev. Critical analyses of the electronic band structures showed that the monoclinic phase of Cu?GeS? is a semiconductor while that of the tetragonal phase presented with metallic features as there was no bandgap due to the overlapping of the valence and conduction bands. Diligent examination of the total and partial density of states revealed that the valence band of the monoclinic phase is primarily composed of Cu-3d states, Ge-4p states with a significant contribution from S-3p states while the conduction band is dominated by Ge-4p and Ge-4s states. For the tetragonal phase, the TDOS and PDOS showed that the valence band is dominated by Cu-3d and contributions from the three Ge orbitals and the two S orbitals. The conduction band minimum in the tetragonal phase is also dominated by Ge-4s states with significant contribution from the Ge-4d, 3p states, as well as the S-3s and 3p states. Our findings suggest that the electronic properties of Cu2GeS3 can be tuned by controlling the crystalline phase, making it a promising candidate for future optoelectronic devices.

- Copper germanium sulphide, Albinit, electronic band structure, density of states,

---

References:

1. Araki, H., Chino, K., Kimura, K., Aihara, N., Jimbo, K. & Katagiri, H. (2014). Fabrication of
Cu2GeS3-based thin film solar cells by sulfurization of Cu/Ge stacked precursors. Japanese.
Journal of Applied Physics. 53. 05FW10. 10.7567/JJAP.53.05FW10.
Ramasamy, Parthiban & Kim, Jinkwon. (2015). Wurtzite Cu2GeS3 Nanocrystals: Phase and
Shape Controlled Colloidal Synthesis. Chemistry, an Asian journal. 10. 10.1002/asia.201500199.
Kada, B., Karima, B., Beloufa, N., Abdelkader, B.. Samir, B., Charef, A. & Souheil, B. (2024).
Structural, Electronic And Optical Properties Of Cu2Ges3. A First Principles Study. Annals of
West University of Timisoara - Physics. 2024. 10.2478/awutp-2024-0005.
Xianghe Meng, Pifu Gong, Jinlong Shi, Chunxiao Li, Zheshuai Lin, and Jiyong Yao (2023).
Inorganic chemistry, 62 (28), 10892-10896. Doi:10.1021/acs.inorgchem.3c01553
Wujisiguleng Bao, Fangyuan Qiu and Sachuronggui Bai (2023). Journal of Physics.: Conf.
Ser. 2578 012013. DOI 10.1088/1742-6596/2578/1/012013
X. Li, K. Timmo, M. Grossberg, M. Pilvet, R. Kaupmees, J. Krustok, K. Muska, V. Mikli, M.
Kauk-Kuusik (2022). Study of the structure and optoelectronic properties of Cu2Ge(SexS1-x)3
microcrystalline
powders.
Thin
Solid
Films.
742,139053.
https://doi.org/10.1016/j.tsf.2021.139053.
Leticia M. de Chalbaud, G.Díaz de Delgado, J.M. Delgado, A.E. Mora, V. Sagredo (1997).
Synthesis and single-crystal structural study of Cu2GeS3. Materials Research Bulletin, 32 (10).
1371-1376, 0025-5408, https://doi.org/10.1016/S0025-5408(97)00115-3.



Robert, E.V.C., de Wild, J., Colombara, D., Dale, P. J (2016). "Crystallographic and
optoelectronic properties of the novel thin film absorber Cu2GeS3," Proc. SPIE 9936, Thin Films
for Solar and Energy Technology VIII, 993607. https://doi.org/10.1117/12.2236621
Bagi, Katalin (2009). "Thermoelectric properties and crystal structure of copper monosulfide,
ternary sulfides Cu2GeX3 (X= S, Se)." Journal of Solid State Chemistry 182.6: 1735-1743
Kayakan, K., Al-Shahrani, M., El-Naggar, A. M., Al-Sehemi, A. G., & Samara, A. (2018).
Electrical properties of Cu2GeS3 thin films: Mott's variable range hopping conduction and
photovoltaic applications. Applied Surface Science, 463, 1022-1027.
Mulay, S. A., Ramadan, W., Baras, F., Thaheem, R., Rasekh, M., Al-Kuhaili, M. F., &
Dapurkar, S. E. (2019). Effect of selenium incorporation on electronic and optical properties of
Cu2GeS3 thin films. Solid State Sciences, 95, 105969.
Kosec, T., Holc, J., & Dominko, B. (1992). Cu2 GeS3 - a New Ordered Tetragonal
Chalcopyrite-Type Material. Journal of Solid State Chemistry, 100(2), 299-307.
Gilbert, S. M., Steinmann, V., Kim, D. H., Men, L., Perdew, J. P., Suns, C. K., & Ronald, T.
(2017). Prediction of Zero-Gap Semiconductors from First Principles: The Case of Cu3GeS3.
Journal of Physical Chemistry Letters, 8(13), 3090-3095.

DOWNLOAD PDF

---

Back