ChemNanoMat
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2022
·Vol. 9
·期 1
·e202200400
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IF 3.82
Bo Zhu,Xu Lu,Jiadang Li,Wenhao Xie,Lifei Wang,Qiang Zhang,Jianfeng Fan,Yun Zheng
Graphical The substitution of iso-valent Bi for Sb is adopted to adjust the thermoelectric transport properties of the undoped Mg 3 Sb 2 compound. The improved power factor and figure of merit are obtained accordingly. Bismuth is the most common alloying element for high-performance Mg 3 Sb 2 -based thermoelectric compounds. However, the electrical and thermal transport data is lacking for undoped Mg 3 (Sb, Bi) 2 solid solutions. In this study, theoretical calculation results show that Bi alloying can reduce the band gap of Mg 3 Sb 2 , favoring the regulation of carrier concentration. Both Mg 3 Sb 2 and Mg 3 SbBi compounds present a single band structure on the valence band maximum at Γ of the Brillouin zone. Incorporating the Bi element can slightly increase the density of states (DOS) on the valence band maximum, which is beneficial for the Seebeck coefficient. Mg 3 Sb 2-x Bi x (0≤x≤0.8) compounds were experimentally prepared via ball milling (BM) combined with the spark plasma sintering (SPS) technique. The carrier concentration, electrical conductivity, and power factor of the samples tend to increase with the increasing Bi content. Bismuth alloying significantly reduces the total thermal conductivity in the low-temperature range, with the lowest value of 0.65 Wm −1 K −1 obtained at ∼400 K for the x=0.2 sample. The peak ZT value of 0.077 at 800 K and the average ZT of 0.051 in the temperature range of 450–800 K are obtained for the x=0.2 sample, which is 93% and 219% higher than those of the unalloyed sample, respectively. This work reveals the Bi-alloying induced transport mechanism and provides fundamental thermoelectric data regarding the undoped Mg 3 Sb 2-x Bi x (0≤x≤0.8) solid solutions.
研究领域:
材料科学
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物理学
✓ 已验证
产品关联
DOI
高影响因子
Nanomaterials
·
2022
·Vol. 12
·期 23
·4318
·
IF 5.719
Linyi Zeng,Lun Cai,Zilei Wang,Nuo Chen,Zhaolang Liu,Tian Chen,Yicong Pang,Wenxian Wang,Hongwei Zhang,Qi Zhang,Zuyong Feng,Pingqi Gao
Crystalline silicon solar cells produced by doping processes have intrinsic shortages of high Auger recombination and/or severe parasitic optical absorption. Dopant-free carrier-selective contacts (DF-CSCs) are alternative routines for the next generation of highly efficient solar cells. However, it is difficult to achieve both good passivating and low contact resistivity for most DF-CSCs. In this paper, a high-quality dopant-free electron-selective passivating contact made from ultra-low concentration water solution is reported. Both low recombination current (J0) ~10 fA/cm2and low contact resistivity (ρc) ~31 mΩ·cm2are demonstrated with this novel contact on intrinsic amorphous silicon thin film passivated n-Si. The electron selectivity is attributed to relieving of the interfacial Fermi level pinning because of dielectric properties (decaying of the metal-induced gap states (MIGS)). The full-area implementation of the novel passivating contact shows 20.4% efficiency on a prototype solar cell without an advanced lithography process. Our findings offer a very simple, cost-effective, and efficient solution for future semiconductor devices, including photovoltaics and thin-film transistors.Keywords:c-Si;solar cell;electron-selective contact;dopant-free;passivation;contact resistivity
研究领域:
材料科学
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光伏技术
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产品关联
DOI
PubMed
高影响因子
Solar RRL
·
2025
·
IF 4.7
Lanxiang Meng,Wenxian Wang,Linkun Zhang,Wenjie Lin,Huili Han,Li Hou,JianJian Fu,Zunwei Zhu,Linghao Zhu,Shishuai Xu,Hui Shen,Zongcun Liang
Dopant-free carrier-selective contacts have the potential to overcome parasitic absorption and doping-related recombination associated with heavy doping. It offers a simpler preparation process and low-temperature fabrication, which has attracted considerable research interest. This study demonstrated a novel full-area dopant-free cesium iodide (CsI, approximately 3 nm thick) as an electron-selective and passivation contact for crystalline silicon (c-Si) solar cells via thermal evaporation, achieving a champion power conversion efficiency of 21.75%. Desired Ohmic contacts, with contact resistivity around 3 mΩ·cm 2 , are formed between lightly doped n-type c-Si and metal electrodes (such as Ag, Al, and Mg) by inserting nanoscale CsI films. CsI film exhibits surprising insensitivity when in contact with the metal electrode. Furthermore, it is found that the thermal evaporation deposition CsI on n-Si exhibits passivation properties at their interface due to the field passivation of n + -n junctions and the chemical passivation of Si-I bonds. Additionally, the stability of CsI is enhanced through thermal annealing, maintaining the stability of contact properties below 300°C. The CsI film offers a dual effect of selective carrier transport and reduced recombination, which simplifies the production process and expands the application of cesium-based materials in photovoltaic devices.
研究领域:
材料科学
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光伏技术
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半导体物理
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产品关联
DOI
高影响因子
MATERIALS RESEARCH BULLETIN
·
2018
·
IF 2.873
Wenjie Lin,Weiliang Wu,Jie Bao,Zongtao Liu,Kaifu Qiu,Lun Cai,Zhirong Yao,Youjun Deng,Zongcun Liang,Hui Shen
The dopant-free back contact solar cells are demonstrated based on hole selective contact material, chromium trioxide (CrO x , x < 3) with a low melting point for high stability and high performance. In this contribution, CrO x is first applied in silicon based solar cell as the emitter. Integrating 5 nm CrO x and 2 nm LiF x into solar cell as the emitter and the back surface filed, resulted in a device efficiency of 13.6%. For further improvement, the back contact solar cell reaching an efficiency of 15.8% was fabricated, by implementing the multilayer films of CrO x (5 nm)/Au (4 nm)/ CrO x (5 nm) as the emitter. The formation of Cr(OH) 3 in ambient condition, resulted in a lower work function (4.8 eV) of the CrO x film. Furthermore, the multilayer back contact solar cell demonstrated a high stability due to CrO x covered with 500 nm Ag, when stored in ambient air longer than 170 days.
研究领域:
材料科学
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光伏技术
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半导体器件
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表面工程
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能源材料
✓ 已验证
DOI
高影响因子
ORGANIC ELECTRONICS
·
2018
·
IF 3.68
Junjie Guo,Xianfang Meng,Hongwei Zhu,Mengmeng Sun,Yibo Wang,Weina Wang,Mingyu Xing,Fei Zhang
Three novel dopant-free hole-transporting materials (HTMs) based on phthalocyanine core containing (4-methyl formate) phenoxy or (4-butyl formate) phenoxy as the peripheral groups with cupper or zinc as the core metals (CuPcNO 2 -OMFPh, CuPcNO 2 -OBFPh, ZnPcNO 2 -OBFPh) were designed and synthesized. All of the phthalocyanine complexes show excellent thermal stabilities, appropriate energy levels and suitable hole mobilities. The potential of three HTMs were tested in perovskite solar cells (PSCs) and ZnPcNO 2 -OBFPh based PSC obtained power conversion efficiency (PCE) of 15.74% under 100 mA cm −2 standard AM 1.5G solar illumination. Most important of all, PSC based on ZnPcNO 2 -OBFPh shows better stability than that of the other two phthalocyanines and Spiro-OMeTAD under continuous light irradiation at 60 °C and maximum power point tracking in ambient air without encapsulation after 500 h. The results show that the introduction of appropriate peripheral groups and core metals can improve the performance and stability of PSCs dramatically, which provides an alternative way to develop HTMs for efficient and stable PSCs.
研究领域:
材料科学
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太阳能
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有机电子学
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产品关联
DOI
高影响因子
Journal of Materials Chemistry C
·
2024
·Vol. 12
·期 22
·8145-8152
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IF 5.7
Dongkai Hu,Mavlanjan Rahman,Shuifu Liu,Lina Shen,Pengpeng Dai,Dawei Wen,Mingmei Wu
While numerous approaches have been devised to optimize the luminescence properties of Eu2+-activated phosphors, the quest for a simple design strategy to achieve color-tunable Eu2+ emission remains a significant challenge. Here, we present a straightforward, doping-free method to tailor the site occupation of Eu2+ and modify its luminescence properties. In the pristine sample, the NaBaB9O15 (NBB) host featuring two cation sites (Na+ and Ba2+), Eu2+ exclusively occupies the Ba2+ site, resulting in blue emission when the NBB:Eu2+ phosphor is synthesized in a H2 reducing atmosphere. When we use CO instead of a H2 reducing atmosphere, impressively, the formation energy required for heterovalent substitution of Na+ by Eu2+ is lowered, leading to the emergence of a distinct green emission band. Significantly, the resultant phosphor NBB:Eu2+@CO exhibits not only a high internal quantum yield of 85.1% and zero-thermal-quenching behavior within the temperature range of 25–200 °C but also wavelength-tunable emission. Benefitting from the multi-color luminescence of the NBB:Eu2+@CO phosphor, its optical applications will no longer be confined to general lighting but extend to anti-counterfeiting and encryption. This study provides a novel design methodology for optimizing the optical properties of Eu2+-activated phosphors.
研究领域:
材料科学
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光学
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化学
✓ 已验证
DOI
高影响因子
Advanced Energy Materials
·
2019
·Vol. 9
·期 26
·1901019
·
IF 24.884
Yaomiao Feng,Qikun Hu,Ehsan Rezaee,Minzhang Li,Zong-Xiang Xu,Andrea Lorenzoni,Francesco Mercuri,Michele Muccini
A power conversion efficiency (PCE) as high as 19.7% is achieved using a novel, low-cost, dopant-free hole transport material (HTM) in mixed-ion solution-processed perovskite solar cells (PSCs). Following a rational molecular design strategy, arylamine-substituted copper(II) phthalocyanine (CuPc) derivatives are selected as HTMs, reaching the highest PCE ever reported for PSCs employing dopant-free HTMs. The intrinsic thermal and chemical properties of dopant-free CuPcs result in PSCs with a long-term stability outperforming that of the benchmark doped 2,2′,7,7′-Tetrakis-( N , N -di- p -methoxyphenylamine)-9,9′-Spirobifluorene (Spiro-OMeTAD)-based devices. The combination of molecular modeling, synthesis, and full experimental characterization sheds light on the nanostructure and molecular aggregation of arylamine-substituted CuPc compounds, providing a link between molecular structure and device properties. These results reveal the potential of engineering CuPc derivatives as dopant-free HTMs to fabricate cost-effective and highly efficient PSCs with long-term stability, and pave the way to their commercial-scale manufacturing. More generally, this case demonstrates how an integrated approach based on rational design and computational modeling can guide and anticipate the synthesis of new classes of materials to achieve specific functions in complex device structures.
研究领域:
材料科学
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可再生能源
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光伏技术
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化学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
InfoMat
·
2023
·Vol. 6
·期 1
·e12491
·
IF 22.7
Mengyu Hong,Xiankun Zhang,Yu Geng,Yunan Wang,Xiaofu Wei,Li Gao,Huihui Yu,Zhihong Cao,Zheng Zhang,Yue Zhang
Metal–semiconductor contacts are crucial components in semiconductor devices. Ultrathin two-dimensional transition-metal dichalcogenide semiconductors can sustain transistor scaling for next-generation integrated circuits. However, their performance is often degraded by conventional metal deposition, which results in a high barrier due to chemical disorder and Fermi-level pinning (FLP). Although, transferring electrodes can address these issues, they are limited in achieving universal transfer of full-class metals due to strong adhesion between pre-deposited metals and substrates. Here, we propose a nanobelt-assisted transfer strategy that can avoid the adhesion limitation and enables the universal transfer of over 20 different types of electrodes. Our contacts obey the Schottky–Mott rule and exhibit a FLP of S = 0.99. Both the electron and hole contacts show record-low Schottky barriers of 4.2 and 11.2 meV, respectively. As a demonstration, we construct a doping-free WSe 2 inverter with these high-performance contacts, which exhibits a static power consumption of only 58 pW. This strategy provides a universal method of electrode preparation for building high-performance post-Moore electronic devices.
研究领域:
材料科学
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纳米电子学
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半导体器件
·
凝聚态物理
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）