INORGANIC CHEMISTRY
·
2019
·
IF 4.85
Zhizhen Wang,Zhen Song,Lixin Ning,Zhiguo Xia,Quanlin Liu
The Sr3SiO5:Eu2+ phosphor has attracted considerable attention for applications in white LEDs owing to its highly efficient yellow emission under violet-blue excitation. We report herein an enhancement of yellow persistent luminescence in Sr3SiO5:Eu2+ through Ge incorporation. The strongest persistent luminescence intensity is observed for Sr3(Si1–xGex)O5:Eu2+ with x = 0.005 with a peak emission wavelength at ∼580 nm and a persistent time of ∼7000 s at the 0.32 mcd/m2 threshold value after UV radiation. A combination of thermoluminescence measurements and density functional theory (DFT) calculations reveals that the afterglow enhancement is due to a significant increase in the number of oxygen vacancies that act as electron trapping centers with appropriate trap depths. This investigation is anticipated to encourage more exploration of GeSi substitution to design and improve Si-containing persistent phosphors with superior functionalities.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry A
·
2022
·Vol. 10
·期 38
·20489-20496
·
IF 14.511
Weihua Wang,Xiaowei Lu,Lin Sun,Jipeng Luo,Quan Shi,Na Ta,Peng Jiang,Xinhe Bao
Thermoelectric materials, which can directly convert thermal energy into electricity, play an important role in waste heat recovery. Sb2Si2Te6 is a promising medium-temperature thermoelectric material for power generation. However, its application is restricted by the relatively low power factor (PF) and the decompostion at high temperature. Herein, we successfully improved the power factor of Sb2Si2Te6 by doping with germanium (Ge). Benefiting from the optimized carrier concentration, the power factor of Sb2Si1−xGexTe6 remains higher than 1100 μW m−1 K−2 from 473 K to 773 K and the highest zT value reaches 1.0 at 773 K. Furthermore, the power generation performance of a single-pair thermoelectric module, consisting of Sb2Si1.94Ge0.06Te6 and Mg3.2Sb1.5Bi0.49Te0.01, is evaluated by three-dimensional numerical simulation. The simulated conversion efficiency is as high as 13% at a temperature difference of 500 K, and the power density can reach up to 3 W cm−2. Our results demonstrate that Ge doping can effectively modify the thermoelectric properties of Sb2Si2Te6 and improve its power generation performance, paving the way for realistic applications in the medium-temperature region.
研究领域:
材料科学
·
能源工程
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2020
·
IF 3.83
Misganaw Alemu Zeleke,Dong-Hau Kuo
The quaternary chalcogenide Cu 2 Zn(Sn 1-x Ge x )(S,Se) 4 bulks, where x is G e / [ G e + S n ] molar ratios of 0, 0.15, 0.30, and 0.45 were synthesized via reactive liquid phase sintering at 600 °C for 30 min in the tube furnace and characterized systematically. Together with Sb 2 S 3 as a reactive liquid phase sintering aid, the effects of Ge incorporation on densification, grain boundary, crystal phase purity, crystalline size, and electrical properties were studied. The morphology of the resulted Cu 2 Zn(Sn 1-x Ge x )(S,Se) 4 bulk was found to be more densified and compacted at G e / [ G e + S n ] molar ratio of 0.15 compared to the rests. The X-ray diffraction peaks were shifted towards a higher angle as Ge fraction was increased. The hole concentrations for the entirely p-type bulks were determined to be 3.67 × 10 18 , 1.40 × 10 18 , 1.28 × 10 18 , and 8.90 × 10 17 cm −3 at G e / [ G e + S n ] molar ratios of 0, 0.15, 0.30, and 0.45, respectively. The effects on conductivity and mobility were consistent with their interrelations. Hence, the synthesis and study of Ge incorporated Cu 2 ZnSn(S,Se) 4 bulk using powder technique allows identifying the composition which is expectedly more important for the fabrication of thin film solar cells.
研究领域:
材料科学
·
太阳能电池技术
✓ 已验证
产品关联
DOI
高影响因子
Crystals
·
2025
·Vol. 15
·期 7
·622
·
IF 2.4
Haoyu Zhao,Junliang Zhu,Zhonghe Zhu,Lin Bo,Wenying Wang,Xingshuo Liu,Changcun Li,Degang Zhao
Cubic phase SnSe-based materials have great potential in the field of thermoelectricity due to their reduced carrier scattering, increased band degeneracy, and ultra-low lattice thermal conductivity. Nevertheless, systematic studies on the influence of element doping on the thermoelectric properties of cubic SnSe-based materials are still relatively scarce. To enrich the research in this field, this work investigates the effects of Ge doping on the phase composition, electrical and thermal transport properties of cubic Sn0.50Ag0.25Bi0.25Se0.50Te0.50thermoelectric materials. X-ray diffraction (XRD) analysis confirmed that the Ge-doped samples exhibited a single cubic phase structure, while scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS) revealed a uniform distribution of elements within the samples. The results indicate that increasing the Ge doping content substantially enhances their electrical conductivity, albeit at the expense of elevated thermal conductivity. By optimizing the content of Ge-doping, the thermoelectric figure of merit (ZT) reached 0.74 at 750 K. Notably, while moderate Ge doping enhances electrical transport properties, excessive doping leads to a significant rise in thermal conductivity, ultimately constraining further thermoelectric performance gains.
✓ 已验证
产品关联
DOI
高影响因子
Nanoscale
·
2016
·Vol. 8
·期 19
·10160-10165
·
IF 7.76
Wangen Zhao,Daocheng Pan,Shengzhong (Frank) Liu
Cu2ZnSn(S,Se)4 (CZTSSe) semiconductors have been a focus of extensive research effort owing to low-toxicity, high abundance and low material cost. Yet, the CZTSSe thin film solar cell has a low open-circuit voltage value that presents challenges. Herein, using GeSe2 as a new Ge source material, we have achieved a wider band gap CZTSSe-based semiconductor absorber layer with its band-gap controlled by adjusting the ratio of SnS2 : GeSe2 used. In addition, the Cu2Zn(Sn,Ge)(S,Se)4 thin films were prepared with optimal Ge doping (30%) and solar cells were fabricated to attain a respectable power conversion efficiency of 4.8% under 1.5 AM with an active area of 0.19 cm2 without an anti-reflection layer.
研究领域:
材料科学
·
光伏技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Advanced Energy Materials
·
2022
·Vol. 12
·期 10
·2103690
·
IF 29.698
Fanqi Meng,Bingcheng Yu,Qinghua Zhang,Yuqi Cui,Shan Tan,Jiangjian Shi,Lin Gu,Dongmei Li,Qingbo Meng,Cewen Nan
Aiming at stable CsPbI 3 perovskite solar cells, Ge incorporated for the first time into DMAPbI 3 -based precursor systems. Ge incorporation is found to be able to modify crystallization growth of CsPb 1− x Ge x I 3 films and reduce annealing temperature and treatment time by lowering CsPbI 3 formation energy. The champion power conversion efficiency (PCE) of 19.52% is achieved with a certified PCE of 18.8%, which is the highest performance of CsPbI 3 PSCs with alien element-doping. In addition, in situ formation of GeO 2 can passivate the grain boundary and surface defects, thus significantly improving the moisture resistance of the perovskite film and related devices. Excellent operational stability is achieved with no PCE degradation over 3000 h at a fixed bias voltage of 0.85 V under continuous white LED (6500 K) illumination and a nitrogen atmosphere. This work demonstrates that Ge-incorporation is a promising way to stabilize CsPbI 3 perovskite solar cells by simultaneously improving perovskite crystallinity and passivating the grain boundary and interfacial defects.
研究领域:
材料科学
·
能源技术
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2020
·
IF 3.83
Xiaogong Lv,Chengjun Zhu,Huimin Hao,Ruijian Liu,Yiming Wang,Junzhen Wang
In this work, Cu 2 ZnSn 1- x Ge x S 4 (CZTGS) precursor thin films with varied Ge composition ( x = 0, 0.2, 0.4, 0.6, 0.8, and 1) were prepared by using a water-based solution approach. After selenizing at 550 °C for 10 min in a graphite box containing selenium powder, the as-fabricated kesterite Cu 2 ZnSn 1- x Ge x (S,Se) 4 (CZTGSSe) thin films were systematically investigated for phase structure, morphology, valence states of elements, optical properties , and electrical properties. The results showed that the Ge element was successfully incorporated into the host lattice of Cu 2 ZnSn(S,Se) 4 (CZTSSe), and kesterite CZTGSSe films were formed. As the Ge content increased, the crystal grains in the films grew larger and showed uniform morphology on the sample surfaces. The band gap in the CZTGS(Se) thin films could be engineered in the range of 1.21 eV–2.00 eV by tuning the relative compositions of the Ge elements. Furthermore, it was confirmed that the doping of Ge improved the mobility, resistivity, and photoelectric performance of the films. Finally, the Cu 2 ZnSn 0.8 Ge 0.2 (S,Se) 4 solar cell device with an efficiency of 5.39% was prepared. The results indicate that non-toxic water solution-based CZTGSSe films showed potential for application in solar cells.
研究领域:
材料科学
·
太阳能电池技术
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry A
·
2025
·
IF 9.5
Ruiping Chen,Yan Wang,Saqib Nawaz Khan,Feifei Xing,Simiao Li,Yiheng Rao,Hao Wang,Zengxia Mei
All-inorganic CsPb(I1-xBrx)3 perovskite solar cells (PSCs) have increasingly broken record power conversion efficiency (PCE), however the poor stability in humid environment is still a serious bottleneck. To suppress the humidity-caused rapid transformation from black phase to yellow phase, germanium (Ge) doping is introduced to improve the tolerance factor of CsPb1-xGexI2.85Br0.15 and its photoelectric performance. A combined investigation of the structural and optical properties reveals a successful substitution of lead (Pb) with Ge in the films as well as a champion PCE of 19.70% for the 1% Ge doped PSC. More significantly, the Ge doped device retained 91.5% of its initial efficiency after being stored in air for 500 hours without any encapsulation process, in contrast to the 83.7% for the undoped counterpart.
研究领域:
材料科学
·
可再生能源
·
光子学
✓ 已验证
产品关联
DOI
高影响因子
Small
·
2024
·Vol. 20
·期 32
·2312003
·
IF 13
Mohammad Nisar,Adeel Abbas,Junze Zhang,Fu Li,Zhuanghao Zheng,Guangxing Liang,Ping Fan,Yue-Xing Chen
Enhancing the thermoelectric performance of n-type polycrystalline SnSe is essential, addressing challenges posed by elevated thermal conductivity and compromised power factor inherent in its intrinsic p-type characteristics. This investigation utilized solid-state reactions and spark plasma sintering techniques for the synthesis of n-type SnSe. A significant improvement in the figure of merit (ZT) is achieved through strategic reduction in Se concentration and optimization of crystal orientation. The co-doping with Br and Ge further improves the material; Br amplifies carrier concentration, enhancing electrical conductivity, while Ge introduces effective phonon scattering centers. In the Br/Ge co-doped SnSe sample, thermal conductivity dropped to 0.38 Wm⁻¹K⁻¹, yielding a remarkable power factor of 662 µW mK − 2 at 773 K, culminating in a ZT of 1.34. This signifies a noteworthy 605% improvement over the pristine sample, underscoring the pivotal role of Ge doping in enhancing n-type material thermoelectric properties. The enhancement is attributed to Br doping introducing additional electronic states near the valence band, and Ge doping modifying the band structure, fostering resonant states near the conduction band. The Br/Ge co-doping further transforms the band structure, influencing electrical conductivity, Seebeck coefficient, and thermal conductivity, advancing the understanding and application of n-type SnSe materials for superior thermoelectric performance.
研究领域:
材料科学
·
热电材料
·
固体物理
·
凝聚态物理
✓ 已验证
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2013
·
IF 3.777
Mian Huang,Wei Xu,Yang Shen,Yuan-Hua Lin,Ce-Wen Nan
Ge-doped Li 7 La 3 Zr 2 O 12 (LLZ) is prepared via the conventional solid-state reaction. Our results showed that doping Ge of less than 1 wt% could stabilize the cubic phase of garnet-type LLZ and also increase its ionic conductivity up to 8.28 × 10 −4 S/cm at room temperature . When the content of Ge dopant is higher, GeO 2 impurity phase would appear and there coexists cubic and tetragonal mixed structures, lowering the conductivity. By combining X-ray absorption near-edge spectroscopy and full multiple-scattering theory, we find that Ge more likely enters into the Li and La crystallographic sites instead of the Zr site, which provides understanding of the micro-structural modulation by Ge dopants and the subsequent enhancement in the ionic conductivity.
研究领域:
材料科学
·
固体化学
·
光谱学
✓ 已验证
产品关联
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2018
·Vol. 42
·期 11
·9074-9079
·
IF 3.201
Zhixiong Hu,Jiali Sheng,Jiahui Chen,Guoqing Sheng,Yunming Li,Xian-Zhu Fu,Lei Wang,Rong Sun,Ching-Ping Wong
Ge-Doped Li0.33La0.56TiO3 (Ge-LLTO) perovskites are synthesized with various GeO2 contents by solid-state reactions as Li-ion conductive electrolytes for rechargeable all-solid-state Li batteries. After the addition of GeO2, the sinterability and Li ion conductivity are enhanced for the perovskite solid electrolyte. The Li0.43La0.56Ti0.95Ge0.05O3 electrolytes exhibit the highest sinterability and Li ion conductivity among the as-prepared Li0.33+2xLa0.56Ti1−xGexO3 electrolytes. The improvement of Li ion conductivity might be attributed to the improvement of the densification and structural integrity of the LLTO solid electrolyte. The lithium transference number (tLi+) of Ge-doped LLTO is close to 1. Moreover, the Ge-LLTO electrolytes are stable in the potential range of 0–10 V vs. Li/Li+.
研究领域:
材料科学
·
电化学
·
储能技术
·
固体离子学
✓ 已验证
DOI
高影响因子
ACS Catalysis
·
2022
·
IF 13.7
Weiqi Guo,Haolin Luo,Zhi Jiang,Dongxu Fang,Jiasheng Chi,Wenfeng Shangguan,Zhiliang Wang,Lianzhou Wang,Adam F. Lee
Cobalt oxides find widespread application in energy materials as oxygen evolution catalysts (OECs) in the oxygen evolution reaction (OER) and photocatalytic overall water splitting (OWS) reaction. However, the nature of the active cobalt species, their role in these reactions, and possible commonalities remain poorly understand. Here, the impact of (redox-inert) germanium dopants on the physicochemical properties of Co3O4 nanoparticles was investigated in electrochemical oxygen evolution and photocatalytic OWS reactions. A significant enhancement in OER performance on doping is attributed to the restructuring of spinel Co3O4 to serpentine Co3Ge2(OH)5, with the latter transforming to an oxyhydroxide active phase during OER. Combination of the p-type Co3Ge2(OH)5 semiconductor as an OEC with an n-type Bi0.5Y0.5VO4 semiconductor doubles the photocatalytic OWS activity of the latter, resulting in H2 and O2 productivities of ∼175.7 and ∼90.1 μmol/h, respectively. Formation of the composite semiconductor induces an intense internal electric field across the p–n junction, facilitating separation of photogenerated carriers and increased OWS activity, which is also validated in alternative photocatalyst, Al-doped SrTiO3. A similar transformation of serpentine Co3Ge2(OH)5 to an oxyhydroxide was not observed during OWS, indicating that Ge doping confers distinct advantages for electrochemical OER vs photocatalytic OWS.
研究领域:
材料科学
·
电化学
·
光化学
·
催化
·
能源材料
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）