OPTICAL MATERIALS
·
2020
·
IF 2.779
Guonan Cui,Yanchun Yang,Ruilan Chen,Chengjun Zhu
Cations substitutions are known to make much significant contribution on achieving the high-quality kesterite Cu 2 ZnSn(S,Se) 4 thin films . And the optimal ratios of Mn, Ni and Co substitutions are reported to be ~0.05, belong to the low doping to reduce their defect density , which looks like to some extent the effect of Na doping. In this study, learning the research experience of alkali metal doping, we introduced the extra trace Mn 2+ ion into the precursor solution without affecting the compositions of other elements (i.e. Cu, Zn, and Sn), and the effect of trace addition on properties of the absorber layer was also studied. It was discovered that crystalline, electrical properties, and hole carrier concentration of Cu 2 ZnSn(S,Se) 4 thin films increased with an increase of Mn incorporation, and the best doping ratio of Mn/(Cu + Zn + Sn) was considered to be 0.03. In addition, the effect of extra trace Mn-doping on the film thickness and elemental compositions of Cu 2 ZnSn(S,Se) 4 absorber layer were studied in detail.
研究领域:
材料科学
·
半导体物理
·
薄膜制备
·
光伏材料
·
固体化学
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2022
·Vol. 48
·期 13
·18876-18883
·
IF 5.532
Zhixin Ma,Yang Qi,Jun Wang,Xiaoguo Bi,Xu-dong Liu,Xiaodong Li,Ji-guang Li,Xudong Sun
SrTiO 3 is a promising thermoelectric material for applications in harsh environments, owing to its excellent thermoelectric (TE) properties and high-temperature stability. The effect of annealing in carbon powders on the TE properties of SrTiO 3−δ in the [111] direction was experimentally investigated and analysed using first-principles calculation. The electrical conductivity of the SrTiO 3−δ single crystals in the [111] direction increases with an increase in annealing temperature in the range of 1573–1673 K, which is opposite to that in the [510] direction as shown in a previous experiment. This is attributed to the different variation trend of carrier concentration. First-principle calculation results show that the carrier concentration in the [111] direction increases with increasing oxygen vacancy concentration, but it is the opposite in the [510] direction. Strong anisotropy of carrier concentration should be caused by the difference in atomic arrangement, making difference in the amount of free electrons that maybe constrained at high oxygen vacancy in different directions. Although the SrTiO 3−δ single crystal annealed at 1573 K shows a lower electrical conductivity, it obtains higher power factor with the maximum value of 2.24 mW m −1 K −2 at 323 K, which is predominantly due to its higher effective mass. It also yields the highest ZT value of 0.18 at 873 K owing to the lower thermal conductivity . The results of this study are imperative for the design and development of perovskite TE materials.
研究领域:
材料科学
·
凝聚态物理
·
热电材料
·
晶体学
·
固体化学
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2022
·Vol. 48
·期 22
·33967-33975
·
IF 5.532
Ya-nan Li,Ping Wu,Shiping Zhang,Yili Pei,Jinguang Yang,Sen Chen,Li Wang
Adding nanoparticles is a method to regulate the performance of thermoelectric materials. Ca 3 Co 4 O 9 /x MoSi 2 (x = 0, 0.05, 0.10, 0.13, and 0.16) was synthesized by a wet chemical method combined with atmospheric pressure sintering. The XRD and SEM results reveal that there are no other reaction in the samples. The grain size of all samples decrease with increasing MoSi 2 content, and all presented a similar flake morphology. The influence of MoSi 2 on the thermoelectric performance of Ca 3 Co 4 O 9 is systematically analysed. The appropriate addition of nano-MoSi 2 particles can increase the carrier concentration and enhance conductivity of Ca 3 Co 4 O 9 . The electrical conductivity of Ca 3 Co 4 O 9 /0.05 MoSi 2 is 83.16 Scm −1 , which is 49.2% higher than that of Ca 3 Co 4 O 9 at 1080 K. The Seebeck coefficient of the Ca 3 Co 4 O 9 /0.16 MoSi 2 sample reaches 197.56 μVK −1 at 980 K, which is significantly better than that of previously reported samples prepared by the same method. Moreover, combined with the experimental results and the analysis of the effective medium theory model, the addition of MoSi 2 can effectively debase the thermal conductivity of Ca 3 Co 4 O 9 . The thermal conductivity of Ca 3 Co 4 O 9 /0.16 MoSi 2 (∼1.26 Wm −1 K −1 , 1080 K) samples decrease greatly, which is attributed to the influence of interfacial thermal resistance and pores in the Ca 3 Co 4 O 9 /MoSi 2 . The ZT value of the Ca 3 Co 4 O 9 /0.05 MoSi 2 sample increases by 44.4% compare with that of Ca 3 Co 4 O 9 and reaches 0.26 at 1080 K. These results demonstrate that adding an appropriate amount of MoSi 2 particles is one of the methods to enhance the thermoelectric performance of Ca 3 Co 4 O 9 ceramic samples.
研究领域:
材料科学
·
凝聚态物理
·
无机非金属材料
·
能源材料
·
热电转换
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry A
·
2022
·Vol. 10
·期 23
·12429-12437
·
IF 14.511
Shuang Li,Yunxiang Hou,Di Li,Bo Zou,Qingtang Zhang,Yang Cao,Guodong Tang
SnSe is considered one of the most intriguing new thermoelectric materials. Polycrystalline SnSe offers a wide range of thermoelectric applications due to its facile synthetic processing and machinability. Herein, we have achieved a high average ZT of 0.8 as well as a high peak ZT of 1.86 in solution-synthesized porous Zn and Ga codoped SnSe nanosheets, generating a maximum energy conversion efficiency of 13.3%. High-density micro/nanopores are induced in the SnSe matrix, which are more effective for scattering phonons and reducing the thermal conductivity. The high density of micro/nanopores, nanosheet structure and dislocations contribute to an ultralow lattice thermal conductivity (0.157 W m−1 K−1 at 873 K). Meanwhile, Ga incorporation can induce band convergence and create resonance levels, producing a large Seebeck coefficient. Ga and Zn codoping contributes to a sharp increase in carrier concentration and an obviously increased electrical conductivity. The enhanced Seebeck coefficient and increased carrier concentration help in achieving a significant enhancement of the power factor over a wide temperature range in the porous Zn and Ga codoped SnSe nanosheets. Consequently, high thermoelectric performance is realized over a wide temperature range via the decoupling of electron–phonon transport in SnSe. This work opens up a great opportunity for designing prospective materials for thermoelectric applications with the aid of the solution synthesis route.
研究领域:
材料科学
·
凝聚态物理
·
纳米科技
·
能源材料
·
半导体物理
·
热电转换
·
无机功能材料
✓ 已验证
DOI
高影响因子
PHYSICA STATUS SOLIDI A-APPLICATIONS AND MATERIALS SCIENCE
·
2018
·Vol. 215
·期 11
·1700905
·
IF 1.795
Shuping Deng,Decong Li,Liping Zheng,Yu Tang,Zhong Chen,Luqi Sun,Wenting Liu,Lanxian Shen,Shukang Deng
In this work, the effect of Cd and Sn atoms partly substitution for Zn on among crystal growth, thermal stability, mechanical, and electrical transport property in β-Zn 4 Sb 3 is reported. In a series of samples prepared from the atomic ratios of Zn:Sb:Cd:Sn = 4.4:3: x :3 ( x = 0.2, 0.4, 0.6, and 0.8). Carrier concentration of all samples varies from 4.52 × 10 19 to 6.42 × 10 19 cm −3 as carrier mobility changes from 58.27 to 67.93 cm 2 V −1 s −1 at room temperature. As a result, electrical transport properties of the samples are optimized by Cd Sn co-doped. The experimental density of all the samples varies from 6.26 × 10 3 to 6.34 × 10 3 kg m −3 consistent with the theoretical value. The weight loss and melting point of the sample are determined to discuss thermal stability in the heating process in air, indicating that the single crystals β-Zn 4 Sb 3 possess an excellent thermal stability and it is practical importance in the TE application at high temperature. Consequently, the maximal power factor of 1.70 × 10 −3 W m −1 K −2 is achieved at 540 K for the sample with initial Cd content x = 0.2, which is enhanced by 40% compared with the single-doping system in β-Zn 4 Sb 3 .
研究领域:
材料科学
·
热电材料
·
固体物理
·
无机化学
·
功能材料
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2019
·
IF 4.175
Siqi Wang,Zhi Yang,Yuejun Sun,Yu Xiao,Li-Dong Zhao
PbTe-based thermoelectric materials are considered to be a medium-temperature thermoelectric candidates and the high-performance n -type PbTe is urgently to be developed to match its p -type counterpart on account of practical application. Herein, we firstly optimized the carrier density of n -type PbTe through Sb doping, and obtained a maximum ZT value of ∼1.0. Then, based on the optimized carrier density, we introduced ternary compounds AgSb(Se, Te) 2 to suppress the lattice thermal conductivity . Minimum lattice thermal conductivity of n -type PbTe was reduced as low as ∼0.53 W m −1 K −1 and ∼0.62 Wm −1 K −1 through introducing AgSbSe 2 and AgSbTe 2 , respectively. Combining the maintained electrical properties with suppressed thermal conductivity , maximum ZT values ∼1.2 and ∼1.3 were obtained in PbTe+2%AgSbSe 2 and PbTe+2%AgSbTe 2 , respectively. This work provides an effective strategy of synergistically balancing charge and phonon transports in n -type PbTe with ternary AgSb(Se, Te) 2 compounds.
研究领域:
材料科学
·
热电转换
·
凝聚态物理
·
半导体物理
·
功能材料
·
能量转换材料
✓ 已验证
DOI
高影响因子
Small
·
2023
·Vol. 20
·期 3
·2306251
·
IF 13.3
Muchun Guo,Ming Liu,Jianbo Zhu,Yuke Zhu,Fengkai Guo,Wei Cai,Yongsheng Zhang,QinYong Zhang,Jiehe Sui
Chemical bonds determine electron and phonon transport in solids. Tailoring chemical bonding in thermoelectric materials causes desirable or compromise thermoelectric transport properties. In this work, taking an example of CaMg 2 Bi 2 with covalent and ionic bonds, density functional theory calculations uncover that element Zn, respectively, replacing Ca and Mg sites cause the weakness of ionic and covalent bonding. Electrically, Zn doping at both Ca and Mg sites increases carrier concentration, while the former leads to higher carrier concentration than that of the latter because of its lower vacancy formation energy. Both doping types increase density-of-state effective mass but their mechanisms are different. The Zn doping Ca site induces resonance level in valence band and Zn doping Mg site promotes orbital alignment. Thermally, point defect and the change of phonon dispersion introduced by doping result in pronounced reduction of lattice thermal conductivity. Finally, combining with the further increase of carrier concentration caused by Na doping and the modulation of band structure and the decrease of lattice thermal conductivity caused by Ba doping, a high figure-of-merit ZT of 1.1 at 823 K in Zn doping Ca sample is realized, which is competitive in 1–2–2 Zintl phase thermoelectric systems.
研究领域:
材料科学
·
凝聚态物理
·
无机化学
·
能源材料
·
热电转换
✓ 已验证
DOI
高影响因子
CARBON
·
2013
·
IF 5.868
Xiuqing Meng,Sefaattin Tongay,Jun Kang,Zhanghui Chen,Fengmin Wu,Shu-Shen Li,Jian-Bai Xia,Jingbo Li,Junqiao Wu
ZnMg and NbCl 5 were intercalated in graphite and the presence of such molecules between the graphene sheets results in n- and p-type doping, respectively. The doping effect is confirmed by Hall and Raman measurements and the intercalation process is monitored by scanning tunneling microscopy . After intercalation the carrier concentration increase almost an order of magnitude and reaches values as high as 10 19 and 10 18 cm −3 for p- and n-type doping, respectively. For higher intercalation times, the intercalated graphite turns back to be as ordered as pristine one as evidenced by the reduction in the D peak in Raman measurements. Intercalation compounds show remarkable stability allowing us to permanently tune the physical properties of few-layer graphite. Our study has provided a new route to produce stable and functional graphite intercalation compounds and the results can be applied to other graphitic structures such as few-layer graphene on SiC.
研究领域:
凝聚态物理
·
材料科学
·
纳米科技
·
表面科学
·
半导体物理
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）