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doping Electron Transporting Layer:An Effective Method to Enhance J_(SC)of All-Inorganic Perovskite Solar Cells

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Energy & Environmental Materials 2021年第4期4卷 500-501页

作者： Chao Liang Guichuan Xing Joint Key Laboratory of the Ministry of Education Institute of Applied Physics and Materials EngineeringUniversity of MacaoMacaoChina

All-inorganic metal-halide CsPbBr_(3)perovskite has emerged as an attractive photovoltaic material for its outstanding environmental stability.However,due to the wide bandgap,the performance of CsPbBr_(3)perovskite solar cells(PSCs)is limited,especially for the short-circuit current density(J_(SC)).In this issue of Energy&Environmental Materials,Guo et al.employed Nb-doped SnO_(2)as electron transporting layers(ETLs),which could greatly improve the J_(SC)of the PSCs based on all-inorganic CsPbBr_(3).

关键词： all-inorganic perovskite depletion region width doping planar heterojunction

Role of Al and Ti doping in modulating electrical properties of BIVOX system

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Journal of Advanced Ceramics 2019年第4期8卷 489-499页

作者： Diptimayee TRIPATHY Amarjyoti SAIKIA Gyati Tachang TADO Arvind PANDEY Department of Physics North Eastern Regional Institute of Science and TechnologyNirjuli 791109Arunachal PradeshIndia Department of Applied Sciences and Humanities National Institute of Foundry and Forge TechnologyHatiaRanchi 834003JharkhandIndia

The doubly-doped bismuth vanadate with Al and Ti having formula unit, Bi2V1–xAlx/2Tix/2O5.5–δ(0.10 ≤ x ≤ 0.25) was synthesized. The specimens were characterized by scanning electron microscopy(SEM), X-ray diffraction(XRD), Fourier transform infrared(FT-IR), differential scanning calorimetric(DSC), UV–Vis, and electrochemical impedance spectroscopy(EIS) for their structural, thermal, optical, and electrical studies. Influence of both dopant cations(Al and Ti) was observed in the gradual stabilization of the tetragonal phase of Bi2VO5.5–δ with dopant amount. A non-uniform grain growth phenomenon was observed up to x = 0.175, with dopant addition. UV–Vis study revealed the comparatively higher order of oxide ion vacancies for the composition x = 0.175. Impedance spectroscopy measurements indicate a significant decrease of both the grain(Rg) and grain boundary resistances(Rgb) with the rise in temperature and the overall resistance is found to be dominated by the grain interior contribution. Enhancement of ionic conductivity was found in all the compositions in the intermediate temperature range as compared to the parent compound, and the single Al-doped system and the highest value were obtained for x = 0.175.

关键词： ionic conductivity doping phase transition grain growth

Influence of monovalent Bi^+doping on real composition,point defects,and photoluminescence in TlCdCl3 and TlCdI3 single crystals

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Science China Materials 2017年第12期60卷 1253-1263页

作者： Daria N.Vtyurina Polina A.Eistrikh-Geller Galina M.Kuz mlcheva Victor B.Rybakov Evgeny V.Khramov Irina A.Kaurova Dmitry Yu.Chernyshov Vladimir N.Korchak Semenov Institute of Chemical Physics Russian Academy of SciencesMOSCOW 119991Russia Institute of Fine Chemical Technologies Moscow Technological UniversityMoscow 119571Russia Lomonosov State University Moscow 119992Russia National Research Center《Kurchatov Instituters》 Moscow 123182Russia Swiss-Norwegian Beamlines at the European Synchrotron Radiation Facility Grenoble 38000France

The structural features and real compositions with point defects of Bi+-doped TlCdCl_3 and TlCdI_3 single crystals, grown by the Bridgman-Stockbarger technique, are first studied using the X-ray diffraction, X-ray synchrotron radiation, and EXAFS/XANES spectroscopy. In the structures of Bi^+-doped TlCdCl_3 and TlCdI_3 crystals, the Cd, Cl, and I sites are found to be defect-free. The vacancies in the Tl sites and interstitial Bi atoms located in the vicinity of the Tl sites are detected in the structures of both samples. In the Bi^+-doped TlCdCl_3, the presence of a small amount of Bi^+ ions in the Tl^+ sites is possible. The correlation between photoluminescence bands and point defects in the refined structures are determined. Photoluminescence spectra and decay kinetics of the Bi+-doped TlCdCl_3 and TlCdI_3 demonstrate that they are attractive materials for potential applications in photonics.

关键词： single crystal growth doping crystal structure point defects photoluminescence

Realizing n-Type Ge Te through Suppressing the Formation of Cation Vacancies and Bi-doping

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Chinese Physics Letters 2021年第12期38卷 50-56页

作者：张敏胡超亮张奇刘锋韩屾付晨光朱铁军 School of Materials Science and Engineering and State Key Laboratory of Silicon MaterialsZhejiang UniversityZhejiang 310027China

It is known that p-type GeTe-based materials show excellent thermoelectric performance due to the favorable electronic band structure.However,n-type doping in GeTe is of challenge owing to the native Ge vacancies and high hole concentration of about 10^(21)cm^(-3).In the present work,the formation energy of cation vacancies of GeTe is increased through alloying PbSe,and further Bi-doping enables the change of carrier conduction from p-type to n-type.As a result,the n-type thermoelectric performance is obtained in GeTe-based materials.A peak zT of 0.34 at 525 K is obtained for(Ge_(0.6)Pb_(0.4))_(0.88)Bi_(0.12)Te_(0.6)Se_(0.4).These results highlight the realization of n-type doping in GeTe and pave the way for further optimization of the thermoelectric performance of n-type GeTe.

关键词： doping realization performance

Effect of Yb_2O_3 doping on the grain boundary of NiFe_2O_4–10NiO-based cermets after sintering

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International Journal of Minerals,Metallurgy and Materials 2015年第12期22卷 1334-1341页

作者： Han-bing He School of Metallurgy and Environment Central South University Department of Metallurgical Engineering University of Utah

xYb2O3-15（20Ni-Cu）/（85 -x）（NiFe2O4-10NiO）（x = 0, 0.25, 0.5, 0.75, 1.0, 2.0, and 10.0） cermets for aluminum electrolysis were prepared to investigate the effect ofYb2O3 doping on the grain boundary of the cermets after sintering. The results showed that each interface was very clear and that with increasing Yb2O3 content, most of the Yb was evenly distributed at the grain boundary. Moreover, according to the phase composition and microstructural analysis by X-ray diffraction （XRD）, scanning electron microscopy with energy dispersive X-ray spectroscopy （SEM/EDX）, and electron probe microanalysis （EPMA）, YbFeO3 was produced along the grain boundary. The YbFeO3 was concluded to not only have formed from the interaction between the NiFe2O4 or Fe2O3 component and Yb2O3 at the grain boundary of the cermets, but also from the decomposition of NiFe2O4 into NiO and Fe2O3 and the subsequent reaction of Fe2O3 with Yb2O3. Thus, the production of YbFeO3 resulted in a cermet with high relative density, good electrical conductivity, and good corrosion resistance.

关键词： cermets ytterbium oxide doping grain boundaries aluminum electrolysis

Anomalously enhanced thermal stability of phosphorene via metal adatom doping: An experimental and first-principles study

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Nano Research 2016年第9期9卷 2687-2695页

作者： Xuewei Feng Vadym V.Kulish Ping Wu xinke Liu Kah-Wee Ang Department of Electrical and Computer Engineering National University of Singapore4 Engineering Drive 3Singapore 117583Singapore Entropic Interface Group(EIG) Engineering Product DevelopmentSingapore University of Technology and Design(SUTD)8 Somapah RoadSingapore 487372Singapore College of Materials Science and Engineering Shenzhen Engineering Laboratory for Advanced Technology of CeramicsNanshan District Key Lab for Biopolymer and Safety EvaluationShenzhen University3688 Nanhai AvenueShenzhen 518060China

Atomically thin black phosphorus, also known as phosphorene, is an emerging two-dimensional (2D) material, which has attracted increasing attention due to its unique electronic and optoelectronic properties. However, the reduced thermal stability of phosphorene limits its suitability for high-temperature fabrication processes, which could be detrimental for the performance of phosphorenebased devices. Here, we investigate the impact of doping by Al and Hf transition metal adatoms on the thermal stability of phosphorene. The formation of Al–P covalent bonds was found to significantly improve the thermal coefficients of the A g 1 , B2g, and A g 2 phonon modes to 0.00044, 0.00081, and 0.00012 cm–1·°C–1, respectively, which are two orders of magnitude lower than those observed for pristine P–P bonds (~0.01 cm–1·°C–1). First-principles calculations within the density functional theory framework reveal that the observed thermal stability enhancement in the Al-doped material reflects a significantly higher Al binding energy, due to the stronger Al–P bonds compared to the weak van der Waals interactions between adjacent P atoms in the undoped material. The present work thus paves the way towards phosphorene materials with improved structural stability, which could be promising candidates for potential nanoelectronic and optoelectronic applications.

关键词： phosphorene black phosphorus adatom doping transition metals thermal stability

Boosting single-band red upconversion luminescence in colloidal NaErF_4 nanocrystals:Effects of doping and inert shell

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Journal of Rare Earths 2019年第6期37卷 573-579页

作者： Xiangshui Cui Yao Cheng Hang Lin Qingping Wu Ju Xu Yuansheng Wang CAS Key Laboratory of Design and Assembly of Functional Nanostructures and Fujian Key Laboratory of NanomaterialsFujian Institute of Research on the Structure of MatterChinese Academy of Sciences

Single-band red upconversion luminescence(UCL) is vital to in vivo bioimaging as well as "see and treat" biomedicines. Herein, starting with the previously reported β-NaErF4:Tm UCNPs, we examined the effects of both Yb^(3+) doping and inert shell coating on the red-to-green(R/G) ratio for Er3+ based UCL. The doping of Yb^(3+) into the β-NaErF4:Tm3+ core not only enhances the whole UCL intensity, but also raises the R/G ratio by 1.25 times. In addition, the coating of an inert NaYF4 shell, which is usually adopted for the enhancement of UCL intensity, further boosts the R/G value up to as high as 77.92. This work may benefit the potential bioimaging application of single-band red UCL.

关键词： Yb3+ doping Single-band Upconversion luminescence Core-shell nanostructure Rare earths

Effects of 3d-transition metal doping on the electronic and magnetic properties of one-dimensional diamond nanothread

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Chinese Physics B 2020年第6期29卷 358-363页

作者：苗珍珍曹粲张蓓段海明龙孟秋 Institute of Low-dimensional Quantum Materials and Devices School of Physics Science and TechnologyXinjiang UniversityUrumqi 830046China Hunan Key Laboratory of Super Micro-structure and Ultrafast Process School of Physics and ElectronicsCentral South UniversityChangsha 410083China

The diamond nanothread(DNT), a new one-dimensional(1 D) full carbon sp3 structure that has been successfully synthesized recently, has attracted widespread attention in the carbon community. By using the first-principles calculation method of density functional theory(DFT), we have studied the effects of 3 d transition metal(TM) atomic doping on the electronic and magnetic properties of DNT. The results show that the spin-polarized semiconductor characteristics are achieved by doping Sc, V, Cr, Mn, and Co atoms in the DNT system. The magnetic moment ranges from 1.00 μB to 3.00 μB and the band gap value is from 0.35 e V to 2.54 e V. The Fe-doped DNT system exhibits spin-metallic state with a magnetic moment of 2.58 μB, while the Ti and Ni-doped DNT systems are nonmagnetic semiconductors. These results indicate that the 3 d TM atoms doping can modulate the electronic and magnetic properties of 1 D-DNT effectively, and the TM-doped DNT systems have potential applications in the fields of electronics, optoelectronics, and spintronics.

关键词： diamond nanothread transition metal atom doping electronic and magnetic property

Synergy of porous structure and cation doping in Ta3N5 photoanode towards improved photoelectrochemical water oxidation

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Journal of Energy Chemistry 2021年第1期30卷 343-350,I0011页

作者： Yubin Chen Hongyu Xia Xiaoyang Feng Ya Liu Wenyu Zheng Lijing Ma Rui Li International Research Center for Renewable Energy State Key Laboratory of Multiphase Flow in Power EngineeringXi’an Jiaotong UniversityXi’an 710049ShaanxiChina

Herein,a cross-linked porous Ta3N5 film was prepared via a simple solution combustion route followed by a high-temperature nitridation process for photoelectrochemical(PEC) water oxidation.Meanwhile,the metal cations(Mg2+ and Zr4+) were incorporated into the porous Ta3N5 to enhance the PEC performance.The porous Mg/Zr co-doped Ta3N5 photoanode yielded a photocurrent density of 1.40 mA cm^(-2) at 1.23 V vs RHE,which is 5.6 times higher than that of the dense Ta3N5 photoanode.The enhanced performance should be ascribed to the synergistic effect of porous structure and cation doping,which can enlarge the electrochemical active surface area and accelerate the charge transfer by introducing ON substitution defects.Subsequently,Co(OH)2 cocatalyst was loaded on the Mg/Zr-Ta3N5 photoanode to negatively shift the onset potential to 0.45 V vs RHE and further improve the photocurrent density to 3.5 mA cm^(-2)at 1.23 V vs.RHE,with a maximum half-cell solar to hydrogen efficiency of 0.45%.The present study provides a new strategy to design efficient Ta3N5 photoelectrodes via the simultaneous control of the morphology and composition.

关键词： Photoelectrochemical water oxidation Ta3N5 Porous structure doping Solution combustion