ACS Nano
·
2023
·
IF 17.1
Yu Liu,Mingquan Li,Shanhong Wan,Khak Ho Lim,Yu Zhang,Mengyao Li,Junshan Li,Maria Ibáñez,Min Hong,Andreu Cabot
AgSbSe2 is a promising thermoelectric (TE) p-type material for applications in the middle-temperature range. AgSbSe2 is characterized by relatively low thermal conductivities and high Seebeck coefficients, but its main limitation is moderate electrical conductivity. Herein, we detail an efficient and scalable hot-injection synthesis route to produce AgSbSe2 nanocrystals (NCs). To increase the carrier concentration and improve the electrical conductivity, these NCs are doped with Sn2+ on Sb3+ sites. Upon processing, the Sn2+ chemical state is conserved using a reducing NaBH4 solution to displace the organic ligand and anneal the material under a forming gas flow. The TE properties of the dense materials obtained from the consolidation of the NCs using a hot pressing are then characterized. The presence of Sn2+ ions replacing Sb3+ significantly increases the charge carrier concentration and, consequently, the electrical conductivity. Opportunely, the measured Seebeck coefficient varied within a small range upon Sn doping. The excellent performance obtained when Sn2+ ions are prevented from oxidation is rationalized by modeling the system. Calculated band structures disclosed that Sn doping induces convergence of the AgSbSe2 valence bands, accounting for an enhanced electronic effective mass. The dramatically enhanced carrier transport leads to a maximized power factor for AgSb0.98Sn0.02Se2 of 0.63 mW m–1 K–2 at 640 K. Thermally, phonon scattering is significantly enhanced in the NC-based materials, yielding an ultralow thermal conductivity of 0.3 W mK–1 at 666 K. Overall, a record-high figure of merit (zT) is obtained at 666 K for AgSb0.98Sn0.02Se2 at zT = 1.37, well above the values obtained for undoped AgSbSe2, at zT = 0.58 and state-of-art Pb- and Te-free materials, which makes AgSb0.98Sn0.02Se2 an excellent p-type candidate for medium-temperature TE applications.
研究领域:
材料科学
·
表面化学
·
热电材料
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Nanoscale
·
2015
·Vol. 8
·期 4
·2277-2283
·
IF 7.394
Shuo Chen,Xvsheng Qiao,Fengxia Wang,Qun Luo,Xianghua Zhang,Xia Wan,Yang Xu,Xianping Fan
An effective colloidal process involving the hot-injection method is developed to synthesize uniform single-crystalline Sb2Se3 nanorods in high yields. The photoconductive characteristics of the as-synthesized Sb2Se3 nanorods are investigated by developing a film-based photodetector and this device displays a remarkable response to visible light with an “ON/OFF” ratio as high as 50 (with an incident light density of 12.05 mW cm−2), short response/recovery times and long-term durability. To overcome the challenge of the intrinsic low electrical conductivity of Sb2Se3, hybrid nanorods with the Sb2Se3/AgSbSe2 heterojunction structure having a type-II band alignment are firstly prepared. The electric current of the photodetector based on the Sb2Se3/AgSbSe2 hybrid nanorod film has been significantly increased both in the dark and under light illumination. The responsivity of the photodetector based on the Sb2Se3/AgSbSe2 hybrid nanorod film is about 4.2 times as much as that of the photodetector based on the Sb2Se3 nanorod film. This improvement can be considered as an important step to promote Sb2Se3 based semiconductors for applications in high performance photodetectors.
研究领域:
材料科学
·
纳米技术
·
光电子学
✓ 已验证
DOI
高影响因子
ADVANCED MATERIALS
·
2025
·Vol. 37
·期 26
·2503496
·
IF 26.8
Kaiqi Zhang,Yuling Huang,Shuang Liu,Qihong Xiong,Sikang Zheng,Bin Zhang,Guiwen Wang,Yu Pan,Guang Han,Guoyu Wang,Xu Lu,Xihan Chen,Xiaoyuan Zhou
Thermoelectric materials, like other electronic materials, require high carrier mobility, which is governed by carrier scattering potential. In addition to intrinsic acoustic phonon scattering, the extrinsic factors such as microstructure and atomic arrangement also have great influence on carrier transport in solids, e.g., the emerging thermoelectric material AgSbSe 2 with strong cation disorder. However, the experimental evaluation of total carrier scattering potential and distinguishing the contributions from intrinsic and extrinsic scatterings is challenging at present. Here, the time-resolved ultrafast spectroscopy analysis utilizing a pump-probe scheme is performed to characterize the charge carrier dynamics of AgSbSe 2 with femtosecond time resolution quantitatively. A significantly lowered total carrier scattering potential energy in Cd-doped AgSbSe 2 crystal is determined, resulting from the elimination of grain boundaries and the presence of short-range order that leads to a negative extrinsic scattering potential. The reduction in carrier scattering potential leads to a threefold increase in the average power factor from 323 to 723 K. A maximum thermoelectric figure of merit of 1.7 is achieved in high-quality AgSb 0.973 Cd 0.017 Se 2 crystal at 723 K, with the output efficiency of the single-leg thermoelectric device reaching a competitive value of 8%. This work reveals how to effectively characterize and modulate carrier scattering potential in thermoelectric compounds.
研究领域:
材料科学
·
热电学
·
凝聚态物理
·
超快光谱学
·
固体物理
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF SOLID STATE CHEMISTRY
·
2020
·
IF 2.726
Xiao-Cun Liu,Yan-Min Wang,Mei-Li Qi,Ming-Yan Pan
In this paper, we report remarkably improved thermoelectric properties of p-type Ag-rich AgSbSe 2 . Polycrystalline bulk samples of Ag 1+ x Sb 1- x Se 2 (x = 0, 0.01, 0.02, 0.03) were prepared from high purity elements and densified by spark plasma sintering. The X-ray diffraction analysis indicates the formation of solid solution and Ag 2 Se second phase in Ag-rich samples. The existence of Ag 2 Se precipitates is further confirmed by differential scanning calorimetric measurements and scanning electron microscopy images. The increased carrier concentrations combined with the modified band structures lead to the enhanced power factor in Ag 1+ x Sb 1- x Se 2 . Ag 2 Se particles act as phonon scattering centres and reduce the lattice thermal conductivity. This, together with the increased power factor, further enhances the thermoelectric figure of merit ZT . The maximum ZT value at 673 K increases from 0.44 for pristine AgSbSe 2 to 1.02 for Ag 1.02 Sb 0.98 Se 2 , which is more than two times enhancement.
研究领域:
材料科学
·
热电学
·
固体物理
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry A
·
2023
·Vol. 11
·期 25
·13720-13728
·
IF 11.9
Zheng Ma,Yubo Luo,Wang Li,Yingchao Wei,Chengjun Li,Abubakar Yakubu Haruna,Zhihong Zhang,Xin Li,Qinghui Jiang,Junyou Yang
Point defects play an important role in regulating the electrical and thermal transport properties of thermoelectric materials, but it is always restricted by the solubility of dopants in the matrix. Herein, we demonstrate an effective route to enhance the solubility of Mn from 8% up to 30% in AgSbSe2 through entropy-driven alloying with MnSe. It enables us to largely enhance the carrier concentration and electrical conductivity and also reduce the lattice thermal conductivity of AgSbSe2. As a consequence, (AgSbSe2)0.7(MnSe)0.3 has a high ZT of ∼0.96 at 750 K. Moreover, a further enhanced ZT of 1.18 was achieved in (AgSbSe2)0.7(Mn0.99Se)0.3 at 750 K by the introduced Mn vacancies.
研究领域:
材料科学
·
热电学
·
固态化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）