CHEMISTRY OF MATERIALS
·
2022
·
IF 10.508
Fu Zhang,Xiaoran Sun,Haonan Xie,Xudong Cai,Bolin Zheng,Hua Yu,Enzuo Liu,Xiaojing Hao,Meng Zhang
Despite the remarkable advances of inorganic perovskite solar cells (PSCs) by extrinsic metal doping, the doping mechanism and physical location of doping ions are still ambiguous. Herein, the ion-migration behavior of inorganic PSCs is studied theoretically and experimentally for Sm-doped CsPbI2Br perovskites. The structural characterizations and density functional theory (DFT) calculation confirm the interstitial occupancy of the dopant Sm in the CsPbI2Br perovskite lattice. The ion-migration behavior was systematically unveiled by employing multiple photoelectrochemical techniques. The results show that with Sm interstitial doping in the CsPbI2Br perovskite, the operational stability of PSCs is dramatically improved owing to effectively suppressed ion migration, demonstrated by alleviated VOC change at different scan rates, weaker response to electric poling, faster photocurrent response, higher activation energy of mobile ions, and much more stable maximum power point (MPP) tracking performance. With theoretical model-supported experimental investigation, this research unravels the mechanism of ion-migration suppression in CsPbI2Br PSCs by interstitial doping. This may pave the way to achieve operational stability of PSCs through facile cost-effective practice.
研究领域:
材料科学
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光伏技术
·
理论计算
✓ 已验证
产品关联
DOI
高影响因子
DYES AND PIGMENTS
·
2022
·
IF 5.122
Feifei Lu,Peiyu Tan,Dengfeng Ren,Yuge Han
Poly (aniline) (PANI) is considered an ideal material for the modulation of infrared (IR) radiation due to its excellent electrochromic properties. However, the camphorsulfonic acid doping mechanism which results in emittance modulation is not clearly understood. With the goal of enhancing the IR emittance variation (Δε), a PANI film was synthesized by a chemical oxidation and spraying method, and the doping mechanism of CSA concentration effect on Δε was studied by combining Raman spectra, X-ray photoelectron spectra and density functional theory calculations. The results demonstrate that with increasing camphorsulfonic acid concentration, the effect of the doping concentration on the emittance of PANI/Au films can be divided into two stages: (1) the change in the emittance is mainly caused by the shortening of optical penetration depth either under the state of dopant free (non-doped) or a low CSA doping concentration; (2) the change in emittance is mainly caused by the increase in reflectivity of the PANI layer under the increased doping. Due to the joint action of the two factors, the emittance of the PANI film first increases and then decreases with increasing concentration of CSA, and the maximum Δε (0.45) is realized at 1 M. This paper clarifies the mechanism of PANI films with different CSA dopant concentrations and could provide a way to increase the emittance modulation range by adjusting the concentration of the dopants.
研究领域:
材料科学
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光学
✓ 已验证
DOI
高影响因子
RSC Advances
·
2013
·Vol. 4
·期 8
·3966-3973
·
IF 2.562
Bo Yu,Xuecheng Xu
In situ polymerization and mechanical blending were utilized to fabricate a multi-walled carbon nanotube–polypyrrole (MWNT–PPy) nano-complex dopant for a polyvinyl chloride (PVC) matrix. A low percolation threshold in PVC for this nano-complex dopant was found. A few percent of doping sharply increases the electrical conductivity of PVC. Further doping with this nano-complex dopant still can enhance the conductivity of PVC but with a much slower rate. Based on our experimental results we propose a mechanism to explain the observed phenomenon: the complex conductive units are formed in the nano-complex dopants due to the interaction of MWNT and PPy, with conductivity close to the intrinsic conductivity of MWNT which is much higher than that of PPy. The conductivity increases significantly with a few percent of dopant. The reason is that the interaction of components becomes stronger with continuous doping, forming relatively independent conductive units. The strong doping effect makes the carrier concentration of the units increase significantly so that the conductivity grows, playing a main role in the conductive system of the composite. After the conductivity curve passes the inflection point, further doping can still enhance the conductivity but with a much slower rate. In this phase, the electron delocalization range extends; complex conductive units interconnect and generate the conductive networks; the conjugate degree of the composite increases; the large π conjugated system is built; the carrier mobility increases as well as the conductivity.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
Advanced Science
·
2022
·Vol. 9
·期 32
·2203111
·
IF 17.521
Jing Guo,Ying Liu,Ping-An Chen,Xinhao Wang,Yanpei Wang,Jing Guo,Xincan Qiu,Zebing Zeng,Lang Jiang,Yuanping Yi,Shun Watanabe,Lei Liao,Yugang Bai,Thuc-Quyen Nguyen,Yuanyuan Hu
Doping is of great importance to tailor the electrical properties of semiconductors. However, the present doping methodologies for organic semiconductors (OSCs) are either inefficient or can only apply to some OSCs conditionally, seriously limiting their general applications. Herein, a novel p-doping mechanism is revealed by investigating the interactions between the dopant trityl tetrakis(pentafluorophenyl) borate (TrTPFB) and poly(3-hexylthiophene) (P3HT). It is found that electrophilic attack of the trityl cations on thiophenes results in the formation of tritylated thiophenium ions, which subsequently induce electron transfer from neighboring P3HT chains to realize p-doping. This unique p-doping mechanism enables TrTPFB to p-dope various OSCs including those with high ionization energy (IE ≈ 5.8 eV). Moreover, this doping mechanism endows TrTPFB with strong doping capability, leading to doping efficiency of over 80% in P3HT. The discovery and elucidation of this novel doping mechanism not only points out that strong electrophiles are a class of efficient p-dopants for OSCs, but also provides new opportunities toward highly efficient doping of various OSCs.
研究领域:
材料科学
·
化学
✓ 已验证
DOI
PubMed
高影响因子
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
·
2023
·Vol. 25
·期 10
·7229-7238
·
IF 3.3
Liguo Gao,Zhen He,Cai Xu,Yingjie Su,Jingjing Hu,Tingli Ma
SnO2, the most promising alternative to TiO2 as the electron transport layer (ETL), has attracted great attention for perovskite solar cells (PSCs) due to its high bulk electron mobility, good band energy at the ETL/perovskite interface, and high chemical stability. To enable more efficient carrier transfer and extraction, elemental doping with different metal cations has been studied in SnO2 ETLs. However, the systematic investigation of the doping mechanism lag far behind their efficiency promotion. In this paper, elements of the same main group (Li, Na, K) and period (K, Ca, Ga) have been selected for doping in SnO2. The results showed that among the properties of the dopants, the electronegativity has the greatest influence. The smaller the electronegativity of the doping species, the more conducive it is to carrier transmission and separation. The corresponding mechanism was proposed and discussed. At last, an efficiency of 20.92% of PSCs based on SnO2–K was achieved. In addition, the doped SnO2 is more beneficial for the growth of perovskite crystals, thus reducing grain boundaries and enhancing the stability of the device.
研究领域:
材料科学
·
能源技术
·
物理化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SURFACE & COATINGS TECHNOLOGY
·
2021
·
IF 4.158
Zefei Yu,An Du,Chenyang Wang,Ruina Ma,Yongzhe Fan,Xue Zhao,Xiaoming Cao
Herein, a ZnO-doped plasma electrolytic oxidation (PEO) composite coating was prepared on the surface of a 1060 Al alloy by adding ZnO nanoparticles (ZnO-NPs) to the composite electrolytes of alkaline sodium silicate (Na 2 SiO 3 ) and sodium hexametaphosphate ((NaPO 3 ) 6 ). To efficiently investigate the coating's microstructure, the detached PEO coating was prepared without damage via an electrochemical method. The morphology and phase composition of the PEO coating were analyzed using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM), and X-ray diffraction (XRD), and an incorporation model of ZnO-NPs was established. The results showed that the addition of ZnO-NPs slightly prolonged the anodic oxidation time and increased the breakdown voltage, whereas the working voltage and final voltage decreased slightly. The XRD results indicated that although the addition of ZnO-NPs did not result in the production of Zn-containing phases, it affected the formation and transformation reactions of other phases. SEM micrographs of the fractured cross-section of detached coating and coating/substrate interface indicated that the ZnO-NPs did not enter the interface layer, nor did it participate in the formation of the cap structure at the interface. Based on the experimental results and the “cascade discharge” model, an incorporation model of ZnO-NPs in PEO has been proposed.
研究领域:
材料科学
·
表面工程
✓ 已验证
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2025
·
IF 6.9
Jiaming Guo,Shanhao Ze,Junbiao Wu,Zhiguo Zhang,Cong Luo,Fei Li,Fei Liu,Jing Li,Baodan Liu
In this study, we innovatively fabricated 2D IGZO ultrathin films with several nanometers and tunable compositions using a liquid metal alloy printing method. We systematically studied the relationship between the composition of In-Ga-Zn liquid alloys and the composition of 2D IGZO films and clarified the possible doping mechanism. It was found that the surface film composition was primarily governed by the Gibbs free energy generated from oxide formation. Importantly, Zn and Ga possess a strong and similar competitive oxidation behavior in the oxidation process of liquid InZnGa alloy, leading to the segregation of Ga 2 O 3 and ZnO in the oxide skin of InZnGa alloy. In this case, we control the micro doping level of Zn and Ga to realize the composition tailoring of 2D IGZO films. Additionally, this study also reveals that increasing the Zn content in the film reduces the band gap width, increases channel current, and shows a trend where conductivity and carrier mobility increase. In contrast, the increases of Ga content results in an obvious decline of electrical performance for 2D IGZO films. This study demonstrates the superiority of liquid metal printing in the fabrication of two-dimensional materials and optoelectronic devices.
研究领域:
材料科学
·
纳米技术
·
光电子学
·
薄膜技术
✓ 已验证
产品关联
DOI
高影响因子
Applied Physics Reviews
·
2021
·Vol. 8
·期 3
·
IF 19.162
Zhong Wentao,Liu Xiaozhao,Cheng Qian,Tan Ting,Huang Qianhui,Deng Qiang,Hu Junhua,Yang Chenghao
In recent years, potassium-ion batteries (KIBs) have emerged as a promising alternative candidate to replace lithium-ion batteries for large-scale energy storage devices owing to the natural abundance of potassium and similar mechanism as lithium-ion batteries. In particular, transition metal oxide cathode materials have attracted growing attention due to their high theoretical capacities and low cost compared with other cathode materials. Nevertheless, due to the larger ionic radius of K-ions, transition metal oxide cathode materials suffer from irreversible structural evolution and interlayer-gliding of transition metal layers in potassiation/depotassiation, which results in sluggish kinetics and structural instability. This limited capacity and unsatisfactory cycling properties inhibit the practical application of potassium-ion batteries. It still remains a challenge to develop the suitable cathode materials for potassium-ion batteries. In this work, the interlayer-gliding and irreversible P3–O3 structure transition were suppressed via the replacement of cobalt and iron, and the doping mechanism was investigated by in situ x-ray diffraction. The incorporation of Co ions and Fe ions enlarges the d-space between the transition metal layers, reduces the resistance of K + migration, and provides the buffer spaces to suppress the interlayer-gliding and P3–O3 phase transformation in electrochemical potassium-ion storage, leading to an enhanced rate capability (58 mA h g −1 at 1 A g −1 ) and superior cycling stability (71% after 300 cycles at 200 mA g −1 ). This strategy provides a better understanding for the effect of Co–Fe substitution in suppressing interlayer-gliding and improving electrochemical properties for the development of a novel cathode material for potassium-ion batteries.
研究领域:
材料科学
·
电化学
·
能源存储
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）