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Hongbo Zhao - One of the best experts on this subject based on the ideXlab platform.
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catalytic mechanism of silver in the oxidative dissolution process of Chalcopyrite experiment and dft calculation
Hydrometallurgy, 2019Co-Authors: Rui Liao, Hongbo Zhao, Menglin Sun, Yisheng Zhang, Yanjun Zhang, Guanzhou QiuAbstract:Abstract In this work, combined techniques were utilized to interpret the catalytic mechanism of Ag+ ions in sulfuric acid-ferric sulfate system of Chalcopyrite. Density functional theory (DFT) calculations indicated the favorable adsorption of Ag+ ions on reconstructed (001)-S and (112)-S surfaces of Chalcopyrite, and confirmed the possibility of silver sulfide and sulfur vacancy formations. XPS analysis further indicated the formation of silver sulfide on Chalcopyrite surface. Electrochemical analysis showed that silver catalyzed Chalcopyrite dissolution by enhancing the electrochemical reactivity. In addition, the incorporation of silver atoms into the Chalcopyrite surface might cause a major distortion in its structure and accelerated the diffusion rate of copper atoms mainly because of that the Cu+ ionic radius is much smaller than that of Ag+. As a consequence, the accumulation of passivating species was prevented and the adverse effect of passivation layer mainly consisting of polysulfide and metallic oxides was reduced, thus resulting in high dissolution kinetics. According to the present work, a model for interpreting catalytic mechanisms of Ag+ in Chalcopyrite dissolution is provided.
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the dissolution and passivation mechanism of Chalcopyrite in bioleaching an overview
Minerals Engineering, 2019Co-Authors: Hongbo Zhao, Menglin Sun, Yisheng Zhang, Xian Zhang, Lu QianAbstract:Abstract Chalcopyrite (CuFeS2) is the most abundant copper-containing resource in the earth and is also widely distributed in solid wastes and secondary resources. Biohydrometallurgy (bioleaching) is considered as a promising minerals processing and extractive metallurgy technology because of its environmental and economic advantages over the conventional beneficiation-pyrometallurgy process, and the bioleaching of Chalcopyrite is always a challenge because Chalcopyrite can be easily passivated in bioleaching. Hence, it is important to understand the dissolution process and passivation mechanism of Chalcopyrite in bioleaching. In this paper, the dissolution process and passivation mechanism of Chalcopyrite bioleaching have been summarized and discussed according to previous publications. The reported possible passivating species are mainly S-containing species consisting of polysulfide (Sn2−), elemental sulfur (S0) and insoluble sulfate (SO42−). The effects of physicochemical properties of Chalcopyrite and multiple factors on the dissolution and passivation mechanism of Chalcopyrite bioleaching have been summarized. We particularly discussed the role of redox potential in Chalcopyrite bioleaching and its controlling techniques.
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a strategy to accelerate the bioleaching of Chalcopyrite through the goethite process
Minerals & Metallurgical Processing, 2018Co-Authors: Rui Liao, Yansheng Zhang, Hongbo Zhao, Xiaotao Huang, Jun WangAbstract:Theoretically, controlling redox potential to a relatively low value and inhibiting jarosite formation on the Chalcopyrite surface would be an effective strategy to accelerate the bioleaching of Chalcopyrite. In this work, using limonite as seed crystals, the effects of the goethite precipitation process on the bioleaching of Chalcopyrite were studied for the first time. The bioleaching results showed that the addition of limonite controlled the redox potential in an appropriate range and promoted Chalcopyrite dissolution through the removal of ferric (Fe3+) ions. X-ray diffraction and scanning electron microscope analyses indicate that limonite significantly induced the goethite precipitation process and inhibited the production of jarosite. We conclude that promoting the goethite precipitation process with limonite is an effective strategy in accelerating the bioleaching process of Chalcopyrite.
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comparison of bioleaching and dissolution process of p type and n type Chalcopyrite
Minerals Engineering, 2017Co-Authors: Rui Liao, Hongbo Zhao, Xingxing Wang, Jun Wang, Xiaotao HuangAbstract:Abstract In this work, bioleaching and dissolution processes of Chalcopyrite from three different regions were investigated and compared mainly by leaching experiments, scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and electrochemical analysis. Hall effect experiments showed that one (Chalcopyrite A) belonged to p-type Chalcopyrite whose carrier concentrations were high, while the other two (Chalcopyrite B and C) were both n-type Chalcopyrite whose carrier concentrations were low. A remarkably higher copper extraction of p-type Chalcopyrite could be achieved during bioleaching by L. ferriphilum compared with n-type Chalcopyrite. Redox potential in bioleaching of p-type Chalcopyrite can be maintained at the appropriate range (about 380–480 mV vs. Ag/AgCl) for a longer period of time. Acid consumption in bioleaching of p-type Chalcopyrite was significantly lower than that of n-type Chalcopyrite. SEM analysis indicated that p-type Chalcopyrite was more easily corroded by microorganism than n-type Chalcopyrite. XPS analysis revealed that monosulfide (S2−), disulfide (S22−), polysulfide (Sn2−) and sulfate (SO42−) were the main intermediate species during bioleaching of both p-type and n-type Chalcopyrite. Electrochemical analysis showed that the electrochemical dissolution processes of p-type and n-type Chalcopyrite were similar, while the conductivity and oxidation-reduction rate of p-type Chalcopyrite was significantly higher than those of n-type Chalcopyrite, thus resulting in significant higher electrochemical dissolution kinetics and copper extraction. This work is potentially useful in explaining the inconsistences in Chalcopyrite hydrometallurgy.
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roles of oxidants and reductants in bioleaching system of Chalcopyrite at normal atmospheric pressure and 45 c
International Journal of Mineral Processing, 2017Co-Authors: Hongbo Zhao, Congren Yang, Jun Wang, Wenqing Qin, Lang Tao, Pan Cao, Guanzhou QiuAbstract:Abstract In this work, the roles of dissolved oxygen (O 2 ), Fe 3 + and Fe 2 + and their interactions during Chalcopyrite leaching in basic culture medium at normal atmospheric pressure and 45 °C were investigated by leaching experiments, XPS and electrochemistry analysis. Results showed that Fe 3 + remarkably promoted Chalcopyrite dissolution at the initial stage of leaching process, while easily caused the final passivation at the later stage. Leaching experiments showed that Fe 2 + cannot promote Chalcopyrite dissolution in N 2 atmosphere, while significantly promoted Chalcopyrite dissolution in O 2 atmosphere. XPS and electrochemistry further proved that Fe 2 + cannot directly react with Chalcopyrite, Fe 2 + was steadily oxidized to Fe 3 + by O 2 and caused redox potential at an appropriate range (about 380–480 mV vs. Ag/AgCl), thus eliminating passivation species of polysulfide (S n 2 − ) and promoting Chalcopyrite dissolution. Dissolved oxygen can directly oxidize Chalcopyrite when with no addition of metal ions. In addition, Fe 3 + , rather than O 2 was the main oxidant in leaching system of Chalcopyrite at normal atmospheric pressure. Band theory was used to further interpret the roles of oxidants and reductants in bioleaching system of Chalcopyrite. This work is potentially useful in interpreting the roles of oxidants and reductants in bioleaching system of Chalcopyrite at normal atmospheric pressure and 45 °C.
Guanzhou Qiu - One of the best experts on this subject based on the ideXlab platform.
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influence diversity of extracellular dna on bioleaching Chalcopyrite and pyrite by sulfobacillus thermosulfidooxidans st
Journal of Central South University, 2020Co-Authors: Weimin Zeng, Guanzhou Qiu, Yuxin Cai, Chunwei Hou, Ajuan Liu, Tangjian Peng, Miao Chen, Li ShenAbstract:In this paper, Sulfobacillus thermosulfidooxidans ST was selected for use in bioleaching of pyrite and Chalcopyrite. The adsorption experiments revealed that more cells were adsorbed on the surface of pyrite than on the surface of Chalcopyrite. The role of extracellular DNA (eDNA) in the bioleaching process was investigated by depletion of eDNA using DNase I. The number of cells attached on the Chalcopyrite and pyrite surfaces decreased on a large scale, and the lag phase of cell growth increased, causing the leaching percentages of pyrite and Chalcopyrite to decrease by approximately 11.6% and 20.5%, respectively. The formation and distribution of eDNA secreted during bioleaching was assessed by a fluorescent dye-based method and visualized by confocal laser scanning microscopy (CLSM). The content of eDNA increased with bioleaching time. Furthermore, ST showed a stronger capacity to produce eDNA on the surface of pyrite than on the surface of Chalcopyrite. These results showed that the removal of eDNA has a more significant effect on the bioleaching of Chalcopyrite than on pyrite.
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catalytic mechanism of silver in the oxidative dissolution process of Chalcopyrite experiment and dft calculation
Hydrometallurgy, 2019Co-Authors: Rui Liao, Hongbo Zhao, Menglin Sun, Yisheng Zhang, Yanjun Zhang, Guanzhou QiuAbstract:Abstract In this work, combined techniques were utilized to interpret the catalytic mechanism of Ag+ ions in sulfuric acid-ferric sulfate system of Chalcopyrite. Density functional theory (DFT) calculations indicated the favorable adsorption of Ag+ ions on reconstructed (001)-S and (112)-S surfaces of Chalcopyrite, and confirmed the possibility of silver sulfide and sulfur vacancy formations. XPS analysis further indicated the formation of silver sulfide on Chalcopyrite surface. Electrochemical analysis showed that silver catalyzed Chalcopyrite dissolution by enhancing the electrochemical reactivity. In addition, the incorporation of silver atoms into the Chalcopyrite surface might cause a major distortion in its structure and accelerated the diffusion rate of copper atoms mainly because of that the Cu+ ionic radius is much smaller than that of Ag+. As a consequence, the accumulation of passivating species was prevented and the adverse effect of passivation layer mainly consisting of polysulfide and metallic oxides was reduced, thus resulting in high dissolution kinetics. According to the present work, a model for interpreting catalytic mechanisms of Ag+ in Chalcopyrite dissolution is provided.
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roles of oxidants and reductants in bioleaching system of Chalcopyrite at normal atmospheric pressure and 45 c
International Journal of Mineral Processing, 2017Co-Authors: Hongbo Zhao, Congren Yang, Jun Wang, Wenqing Qin, Lang Tao, Pan Cao, Guanzhou QiuAbstract:Abstract In this work, the roles of dissolved oxygen (O 2 ), Fe 3 + and Fe 2 + and their interactions during Chalcopyrite leaching in basic culture medium at normal atmospheric pressure and 45 °C were investigated by leaching experiments, XPS and electrochemistry analysis. Results showed that Fe 3 + remarkably promoted Chalcopyrite dissolution at the initial stage of leaching process, while easily caused the final passivation at the later stage. Leaching experiments showed that Fe 2 + cannot promote Chalcopyrite dissolution in N 2 atmosphere, while significantly promoted Chalcopyrite dissolution in O 2 atmosphere. XPS and electrochemistry further proved that Fe 2 + cannot directly react with Chalcopyrite, Fe 2 + was steadily oxidized to Fe 3 + by O 2 and caused redox potential at an appropriate range (about 380–480 mV vs. Ag/AgCl), thus eliminating passivation species of polysulfide (S n 2 − ) and promoting Chalcopyrite dissolution. Dissolved oxygen can directly oxidize Chalcopyrite when with no addition of metal ions. In addition, Fe 3 + , rather than O 2 was the main oxidant in leaching system of Chalcopyrite at normal atmospheric pressure. Band theory was used to further interpret the roles of oxidants and reductants in bioleaching system of Chalcopyrite. This work is potentially useful in interpreting the roles of oxidants and reductants in bioleaching system of Chalcopyrite at normal atmospheric pressure and 45 °C.
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Effects of pyrite and bornite on bioleaching of two different types of Chalcopyrite in the presence of Leptospirillum ferriphilum
Bioresource technology, 2015Co-Authors: Hongbo Zhao, Xihua Zheng, Jun Wang, Wenqing Qin, Xiaowen Gan, Lang Tao, Guanzhou QiuAbstract:The effects of pyrite and bornite on bioleaching of two different Chalcopyrite samples by Leptospirillum ferriphilum were studied for the first time. Results showed that bioleaching behaviors of the two Chalcopyrite samples were extremely different. Bornite decreased the redox potential (ORP) and maintained it at an appropriate range (380-480 mV vs. Ag/AgCl) to promote Chalcopyrite (A) dissolution, but caused the redox potential out of the optimum range and inhibited Chalcopyrite (B) dissolution. Large amount of pyrite decreased the redox potential and maintained it at an optimum range to promote Chalcopyrite (A) dissolution, while increased the redox potential and kept it at appropriate range for a longer period of time to enhance the dissolution rate of Chalcopyrite (B). Chalcopyrite (B) had significantly higher values of conductivity and oxidation-reduction rate when compared with those of Chalcopyrite (A). The work is potentially useful in interpreting the inconsistence of the researches of Chalcopyrite hydrometallurgy.
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electrochemical dissolution process of Chalcopyrite in the presence of mesophilic microorganisms
Minerals Engineering, 2015Co-Authors: Hongbo Zhao, Jun Wang, Wenqing Qin, Shan Zhu, Guanzhou QiuAbstract:Abstract The dissolution process of Chalcopyrite in the presence of mesophilic microorganisms was investigated by electrochemical measurements. X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) analysis, accompanied by leaching experiments. Results proved that the presence of Acidithiobacillus ferrooxidans enhanced the initial reduction of Chalcopyrite to intermediate species (Cu 2 S), thus promoting the dissolution of Chalcopyrite in the initial stage of bioleaching. However, Chalcopyrite tended to be directly oxidized to polysulfide (S n 2− ) and CuS in the later stage of bioleaching when redox potential was higher than 0.5 V (vs. Ag/AgCl), the formed polysulfide and jarosite can be responsible for the passivation of Chalcopyrite in the later stage of bioleaching by A . ferrooxidans . On the contrary, Chalcopyrite was mainly directly oxidized to polysulfide and CuS in the presence of sterile 9K medium or Acidithiobacillus thiooxidans , and the initial reduction reaction was still the rate-limiting step, thus resulting in low copper extraction rate.
Jun Wang - One of the best experts on this subject based on the ideXlab platform.
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catalytic effect of silver on copper release from Chalcopyrite mediated by acidithiobacillus ferrooxidans
Journal of Hazardous Materials, 2020Co-Authors: Rui Liao, Baojun Yang, Chunxiao Zhao, Wen Luo, Min Gan, Jun WangAbstract:Abstract Although silver ion in the solution is an important factor affecting the biodissolution of Chalcopyrite, the effect of silver ion on the release of copper ion from Chalcopyrite to the environment has not been explored until now. In order to fill this knowledge gap, the effect of silver ion on copper release from Chalcopyrite in the presence of Acidithiobacillus ferrooxidans was investigated. The results indicate that silver ion significantly enhanced Chalcopyrite biodissolution, thereby releasing more copper ion. In turn, this indicates that the release of copper ion from Chalcopyrite to the environment was increased under these conditions. Biodissolution results, bacterial adsorption experiments, elemental composition analysis, and electrochemical analysis reveal that the enhancement of silver ion on copper ion release from Chalcopyrite was mainly attributed to the improvement of electrochemical activity of Chalcopyrite and the inhibition of the formation of passivation layer (Sn2−/S0) on the Chalcopyrite surface. This study provides a better understanding of the effect of silver ion on the release of copper ion from Chalcopyrite to the environment. In the future, the influence of silver ion on Chalcopyrite biodissolution should be considered in the evaluation of copper ion pollution to ensure reliability.
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a strategy to accelerate the bioleaching of Chalcopyrite through the goethite process
Minerals & Metallurgical Processing, 2018Co-Authors: Rui Liao, Yansheng Zhang, Hongbo Zhao, Xiaotao Huang, Jun WangAbstract:Theoretically, controlling redox potential to a relatively low value and inhibiting jarosite formation on the Chalcopyrite surface would be an effective strategy to accelerate the bioleaching of Chalcopyrite. In this work, using limonite as seed crystals, the effects of the goethite precipitation process on the bioleaching of Chalcopyrite were studied for the first time. The bioleaching results showed that the addition of limonite controlled the redox potential in an appropriate range and promoted Chalcopyrite dissolution through the removal of ferric (Fe3+) ions. X-ray diffraction and scanning electron microscope analyses indicate that limonite significantly induced the goethite precipitation process and inhibited the production of jarosite. We conclude that promoting the goethite precipitation process with limonite is an effective strategy in accelerating the bioleaching process of Chalcopyrite.
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comparison of bioleaching and dissolution process of p type and n type Chalcopyrite
Minerals Engineering, 2017Co-Authors: Rui Liao, Hongbo Zhao, Xingxing Wang, Jun Wang, Xiaotao HuangAbstract:Abstract In this work, bioleaching and dissolution processes of Chalcopyrite from three different regions were investigated and compared mainly by leaching experiments, scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and electrochemical analysis. Hall effect experiments showed that one (Chalcopyrite A) belonged to p-type Chalcopyrite whose carrier concentrations were high, while the other two (Chalcopyrite B and C) were both n-type Chalcopyrite whose carrier concentrations were low. A remarkably higher copper extraction of p-type Chalcopyrite could be achieved during bioleaching by L. ferriphilum compared with n-type Chalcopyrite. Redox potential in bioleaching of p-type Chalcopyrite can be maintained at the appropriate range (about 380–480 mV vs. Ag/AgCl) for a longer period of time. Acid consumption in bioleaching of p-type Chalcopyrite was significantly lower than that of n-type Chalcopyrite. SEM analysis indicated that p-type Chalcopyrite was more easily corroded by microorganism than n-type Chalcopyrite. XPS analysis revealed that monosulfide (S2−), disulfide (S22−), polysulfide (Sn2−) and sulfate (SO42−) were the main intermediate species during bioleaching of both p-type and n-type Chalcopyrite. Electrochemical analysis showed that the electrochemical dissolution processes of p-type and n-type Chalcopyrite were similar, while the conductivity and oxidation-reduction rate of p-type Chalcopyrite was significantly higher than those of n-type Chalcopyrite, thus resulting in significant higher electrochemical dissolution kinetics and copper extraction. This work is potentially useful in explaining the inconsistences in Chalcopyrite hydrometallurgy.
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roles of oxidants and reductants in bioleaching system of Chalcopyrite at normal atmospheric pressure and 45 c
International Journal of Mineral Processing, 2017Co-Authors: Hongbo Zhao, Congren Yang, Jun Wang, Wenqing Qin, Lang Tao, Pan Cao, Guanzhou QiuAbstract:Abstract In this work, the roles of dissolved oxygen (O 2 ), Fe 3 + and Fe 2 + and their interactions during Chalcopyrite leaching in basic culture medium at normal atmospheric pressure and 45 °C were investigated by leaching experiments, XPS and electrochemistry analysis. Results showed that Fe 3 + remarkably promoted Chalcopyrite dissolution at the initial stage of leaching process, while easily caused the final passivation at the later stage. Leaching experiments showed that Fe 2 + cannot promote Chalcopyrite dissolution in N 2 atmosphere, while significantly promoted Chalcopyrite dissolution in O 2 atmosphere. XPS and electrochemistry further proved that Fe 2 + cannot directly react with Chalcopyrite, Fe 2 + was steadily oxidized to Fe 3 + by O 2 and caused redox potential at an appropriate range (about 380–480 mV vs. Ag/AgCl), thus eliminating passivation species of polysulfide (S n 2 − ) and promoting Chalcopyrite dissolution. Dissolved oxygen can directly oxidize Chalcopyrite when with no addition of metal ions. In addition, Fe 3 + , rather than O 2 was the main oxidant in leaching system of Chalcopyrite at normal atmospheric pressure. Band theory was used to further interpret the roles of oxidants and reductants in bioleaching system of Chalcopyrite. This work is potentially useful in interpreting the roles of oxidants and reductants in bioleaching system of Chalcopyrite at normal atmospheric pressure and 45 °C.
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dissolution and passivation mechanisms of Chalcopyrite during bioleaching dft calculation xps and electrochemistry analysis
Minerals Engineering, 2016Co-Authors: Jun Wang, Minghao Hu, Hongbo Zhao, Kaiyun LiAbstract:Abstract In this work, density functional theory (DFT) calculation, X-ray photoelectron spectroscopy (XPS) and electrochemistry analysis were carried out to investigate the dissolution process and passivation mechanisms of Chalcopyrite in the presence of sulfur and iron oxidizing microorganisms. Both DFT calculation and XPS analysis indicated that the formula of Chalcopyrite should be Cu + Fe3 + (S2−)2. Disulfide (S22−) and polysulfide (Sn2−) can be easily formed on the surface of Chalcopyrite due to the surface reconstruction. The dissolution process of Chalcopyrite in bioleaching was mainly dependent on redox potential. Chalcopyrite was predominantly directly oxidized to polysulfide when redox potential was lower than about 350 mV vs. Ag/AgCl and resulted in low dissolution rate. When redox potential was in the range of about 350–480 mV vs. Ag/AgCl, Chalcopyrite was mainly transformed to intermediate species of Cu2S rather than polysulfide, thus resulting in high dissolution rate. When redox potential was higher than about 480 mV vs. Ag/AgCl, Chalcopyrite was principally directly oxidized to polysulfide which caused the passivation of Chalcopyrite. Finally, a model of dissolution and passivation mechanisms of Chalcopyrite in the presence of sulfur and iron oxidizing microorganisms was provided.
Walter R. L. Lambrecht - One of the best experts on this subject based on the ideXlab platform.
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electronic band structure of ordered vacancy defect Chalcopyrite compounds with formulaii iii2 vi4
Physical Review B, 2004Co-Authors: Xiaoshu Jiang, Walter R. L. LambrechtAbstract:First-principles local-density-functional calculations are presented for the electronic band structures of the ordered vacancy defect Chalcopyrites with formula $\mathrm{II}\ensuremath{-}{\mathrm{III}}_{2}\ensuremath{-}{\mathrm{VI}}_{4}$ for $\mathrm{II}=\mathrm{Zn},$ Cd, Hg, $\mathrm{III}=\mathrm{Al},$ Ga, In, and $\mathrm{VI}=\mathrm{S},$ Se, Te. Their relationship with the band structure of their parent Chalcopyrite compounds $\mathrm{I}\ensuremath{-}\mathrm{III}\ensuremath{-}{\mathrm{VI}}_{2}$ with $\mathrm{I}=\mathrm{Cu},$ Ag, and their grand parent II-VI compounds is clarified. An empirical correction for the band gaps beyond local-density approximation is introduced and shown to give good agreement for cases where data are available. The chemical trends are discussed.
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electronic band structure of ordered vacancy defect Chalcopyrite compounds with formula ii iii 2 vi 4
Physical Review B, 2004Co-Authors: Xiaoshu Jiang, Walter R. L. LambrechtAbstract:First-principles local-density-functional calculations are presented for the electronic band structures of the ordered vacancy defect Chalcopyrites with formula $\mathrm{II}\ensuremath{-}{\mathrm{III}}_{2}\ensuremath{-}{\mathrm{VI}}_{4}$ for $\mathrm{II}=\mathrm{Zn},$ Cd, Hg, $\mathrm{III}=\mathrm{Al},$ Ga, In, and $\mathrm{VI}=\mathrm{S},$ Se, Te. Their relationship with the band structure of their parent Chalcopyrite compounds $\mathrm{I}\ensuremath{-}\mathrm{III}\ensuremath{-}{\mathrm{VI}}_{2}$ with $\mathrm{I}=\mathrm{Cu},$ Ag, and their grand parent II-VI compounds is clarified. An empirical correction for the band gaps beyond local-density approximation is introduced and shown to give good agreement for cases where data are available. The chemical trends are discussed.
Xiaoshu Jiang - One of the best experts on this subject based on the ideXlab platform.
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electronic band structure of ordered vacancy defect Chalcopyrite compounds with formulaii iii2 vi4
Physical Review B, 2004Co-Authors: Xiaoshu Jiang, Walter R. L. LambrechtAbstract:First-principles local-density-functional calculations are presented for the electronic band structures of the ordered vacancy defect Chalcopyrites with formula $\mathrm{II}\ensuremath{-}{\mathrm{III}}_{2}\ensuremath{-}{\mathrm{VI}}_{4}$ for $\mathrm{II}=\mathrm{Zn},$ Cd, Hg, $\mathrm{III}=\mathrm{Al},$ Ga, In, and $\mathrm{VI}=\mathrm{S},$ Se, Te. Their relationship with the band structure of their parent Chalcopyrite compounds $\mathrm{I}\ensuremath{-}\mathrm{III}\ensuremath{-}{\mathrm{VI}}_{2}$ with $\mathrm{I}=\mathrm{Cu},$ Ag, and their grand parent II-VI compounds is clarified. An empirical correction for the band gaps beyond local-density approximation is introduced and shown to give good agreement for cases where data are available. The chemical trends are discussed.
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electronic band structure of ordered vacancy defect Chalcopyrite compounds with formula ii iii 2 vi 4
Physical Review B, 2004Co-Authors: Xiaoshu Jiang, Walter R. L. LambrechtAbstract:First-principles local-density-functional calculations are presented for the electronic band structures of the ordered vacancy defect Chalcopyrites with formula $\mathrm{II}\ensuremath{-}{\mathrm{III}}_{2}\ensuremath{-}{\mathrm{VI}}_{4}$ for $\mathrm{II}=\mathrm{Zn},$ Cd, Hg, $\mathrm{III}=\mathrm{Al},$ Ga, In, and $\mathrm{VI}=\mathrm{S},$ Se, Te. Their relationship with the band structure of their parent Chalcopyrite compounds $\mathrm{I}\ensuremath{-}\mathrm{III}\ensuremath{-}{\mathrm{VI}}_{2}$ with $\mathrm{I}=\mathrm{Cu},$ Ag, and their grand parent II-VI compounds is clarified. An empirical correction for the band gaps beyond local-density approximation is introduced and shown to give good agreement for cases where data are available. The chemical trends are discussed.