Co-doped BaFe_(2)As_(2) Josephson junction fabricated with a focused helium ion beam

Josephson junction plays a key role not only in studying the basic physics of unconventional iron-based superconductors but also in realizing practical application of thin-film based devices,therefore the preparation of high-quality iron pnictide Josephson junctions is of great importance.In this work,we have successfully fabricated Josephson junctions from Co-doped BaFe_(2)As_(2)thin films using a direct junction fabrication technique which utilizes high energy focused helium ion beam(FHIB).The electrical transport properties were investigated for junctions fabricated with various He^(+)irradiation doses.The junctions show sharp superconducting transition around 24 K with a narrow transition width of 2.5 K,and a dose correlated foot-structure resistance which corresponds to the effective tuning of junction properties by He^(+)irradiation.Significant J_c suppression by more than two orders of magnitude can be achieved by increasing the He^(+)irradiation dose,which is advantageous for the realization of low noise ion pnictide thin film devices.Clear Shapiro steps are observed under 10 GHz microwave irradiation.The above results demonstrate the successful fabrication of high quality and controllable Co-doped BaFe_(2)As_(2)Josephson junction with high reproducibility using the FHIB technique,laying the foundation for future investigating the mechanism of iron-based superconductors,and also the further implementation in various superconducting electronic devices.

Neutral and metallic vs.charged and semiconducting surface layer in acceptor doped CeO_(2)

The monomolecular surface layer of acceptor doped CeO_(2) may become neutral and metallic or charged and semiconducting.This is revealed in the theoretical analysis of the oxygen pressure dependence of the surface defects concentration in acceptor doped ceria with two different dopant types and operated under different oxygen pressures.Recently published experimental data for highly reduced Sm0.2Ce0.8O1.9-x(SDC)containing a fixed valence dopant Sm3+are very different from those published for Pr0.1Ce0.9O_(2)-x(PCO) with the variable valence dopant Pr4+/Pr3+being reduced under milder conditions.The theoretical analysis of these experimental results fits very well the experimental results of SDC and PCO.It leads to the following predictions:the highly reduced surface of SDC is metallic and neutral,the metallic surface electron density of state is gs=0.9×10^(38)J-1·m^(-2)(1.4×1015eV^(-1)·cm^(-2)),the electron effective mass is meff,s=3.3me,and the phase diagram of the reduced surface has theα(fcc)structure as in the bulk.In PCO a double layer is predicted to be formed between the surface and the bulk with the surface being negatively charged and semiconducting.The surface of PCO maintains high Pr^(3+) defect concentration as well as relative high oxygen vacancy concentration at oxygen pressures higher than in the bulk.The reasons for the difference between a metallic and semiconducting surface layer of acceptor doped CeO_(2) are reviewed,as well as the key theoretical considerations applied in coping with this problem.For that we make use of the experimental data and theoretical analysis available for acceptor doped ceria.

Durable hierarchical phosphorus‐doped biphase MoS_(2)electrocatalysts with enhanced H^(*)adsorption

Phase engineering is an efficient strategy for enhancing the kinetics of electrocatalytic reactions.Herein,phase engineering was employed to prepare high‐performance phosphorous‐doped biphase(1T/2H)MoS_(2)(P‐BMS)nanoflakes for hydrogen evolution reaction(HER).The doping of MoS_(2)with P atoms modifies its electronic structure and optimizes its electrocatalytic reaction kinetics,which significantly enhances its electrical conductivity and structural stability,which are verified by various characterization tools,including X‐ray photoelectron spectroscopy,high‐resolution transmission electron microscopy,X‐ray absorption near‐edge spectroscopy,and extended X‐ray absorption fine structure.Moreover,the hierarchically formed flakes of P‐BMS provide numerous catalytic surface‐active sites,which remarkably enhance its HER activity.The optimized P‐BMS electrocatalysts exhibit low overpotentials(60 and 72 mV at 10 mA cm^(−2))in H_(2)SO_(4)(0.5 M)and KOH(1.0 M),respectively.The mechanism of improving the HER activity of the material was systematically studied using density functional theory calculations and various electrochemical characterization techniques.This study has shown that phase engineering is a promising strategy for enhancing the H*adsorption of metal sulfides.

Unveiling the pressure-driven metal–semiconductor–metal transition in the doped TiS_(2)

Conventional theories expect that materials under pressure exhibit expanded valence and conduction bands,leading to increased electrical conductivity.Here,we report the electrical properties of the doped 1T-TiS_(2) under high pressure by electrical resistance investigations,synchrotron x-ray diffraction,Raman scattering and theoretical calculations.Up to 70 GPa,an unusual metal-semiconductor-metal transition occurs.Our first-principles calculations suggest that the observed anti-Wilson transition from metal to semiconductor at 17 GPa is due to the electron localization induced by the intercalated Ti atoms.This electron localization is attributed to the strengthened coupling between the doped Ti atoms and S atoms,and the Anderson localization arising from the disordered intercalation.At pressures exceeding 30.5 GPa,the doped TiS_(2) undergoes a re-metallization transition initiated by a crystal structure phase transition.We assign the most probable space group as P2_(1)2_(1)2_(1).Our findings suggest that materials probably will eventually undergo the Wilson transition when subjected to sufficient pressure.

Small but mighty:Empowering sodium/potassium-ion battery performance with S-doped SnO_(2) quantum dots embedded in N,S codoped carbon fiber network

SnO_(2) has been extensively investigated as an anode material for sodium-ion batteries(SIBs)and potassium-ion batteries(PIBs)due to its high Na/K storage capacity,high abundance,and low toxicity.However,the sluggish reaction kinetics,low electronic conductivity,and large volume changes during charge and discharge hinder the practical applications of SnO_(2)-based electrodes for SIBs and PIBs.Engineering rational structures with fast charge/ion transfer and robust stability is important to overcoming these challenges.Herein,S-doped SnO_(2)(S-SnO_(2))quantum dots(QDs)(≈3 nm)encapsulated in an N,S codoped carbon fiber networks(S-SnO_(2)-CFN)are rationally fabricated using a sequential freeze-drying,calcination,and S-doping strategy.Experimental analysis and density functional theory calculations reveal that the integration of S-SnO_(2) QDs with N,S codoped carbon fiber network remarkably decreases the adsorption energies of Na/K atoms in the interlayer of SnO_(2)-CFN,and the S doping can increase the conductivity of SnO_(2),thereby enhancing the ion transfer kinetics.The synergistic interaction between S-SnO_(2) QDs and N,S codoped carbon fiber network results in a composite with fast Na+/K+storage and extraordinary long-term cyclability.Specifically,the S-SnO_(2)-CFN delivers high rate capacities of 141.0 mAh g^(−1) at 20 A g^(−1) in SIBs and 102.8 mAh g^(−1) at 10 A g^(−1) in PIBs.Impressively,it delivers ultra-stable sodium storage up to 10,000 cycles at 5 A g^(−1) and potassium storage up to 5000 cycles at 2 A g^(−1).This study provides insights into constructing metal oxide-based carbon fiber network structures for high-performance electrochemical energy storage and conversion devices.

P掺杂β-FeSi_(2)材料的制备与热电输运性能

β-FeSi_(2)作为一种绿色环保、高温抗氧化的热电材料,在工业余热回收领域具有潜在的应用价值。虽然磷(P)是一种理想的β-FeSi_(2)硅(Si)位的n型掺杂元素,但是P掺杂β-FeSi_(2)易出现第二相,从而限制了其热电性能的提升。本研究采用感应熔炼法合成了一系列FeSi_(2)-xPx(x=0,0.02,0.04,0.06)样品,极大程度地避免了第二相的产生,并系统研究了P掺杂对β-FeSi_(2)热电输运性能的影响。结果表明,P在β-FeSi_(2)中的掺杂极限约为0.04,与前期的理论缺陷计算结果相符。此外,P掺杂优化了β-FeSi_(2)的热电性能,在850 K时,FeSi1.96P0.04的最高热电优值ZT约为0.12,远高于已有的研究结果(673 K,最高ZT仅为0.03)。然而,与同为n型Co和Ir掺杂的β-FeSi_(2)相比(其载流子浓度可达10^(22)cm^(-3)),P掺杂β-FeSi_(2)的载流子浓度较低,最高仅为10^(20)cm^(-3),这导致其电声散射效应较弱,从而限制了整体热电性能的提升。若能提高其载流子浓度,则热电性能有望得到进一步提升。

Thermodynamic equilibrium theory-guided design and synthesis of Mg-doped LiFe_(0.4)Mn_(0.6)PO_(4)/C cathode for lithium-ion batteries

Mn-rich LiFe_(1-x)Mn_(x)PO_(4)(x>0.5),which combines the high operation voltage of LiMnPO_(4)with excellent rate performa nce of LiFePO4,is hindered by its sluggish kinetic properties.Herein,thermodynamic equilibrium analysis of Mn^(2+)-Fe^(2+)-Mg^(2+)-C_(2)O_(4)^(2-)-H_(2)O system is used to guide the design and preparation of insitu Mg-doped(Fe_(0.4)Mn_(0.6))_(1-x)Mg_(x)C_(2)O_(4)intermediate,which is then employed as an innovative precursor to synthesize high-performance Mg-doped LiFe_(0.4)Mn_(0.6)PO_(4).It indicates that the metal ions with a high precipitation efficiency and the stoichiometric precursors with uniform element distribution can be achieved under the optimized thermodynamic conditions.Meanwhile,accelerated Li+diffusivity and reduced charge transfer resistance originating from Mg doping are verified by various kinetic characterizations.Benefiting from the contributions of inherited homogeneous element distribution,small particle size,uniform carbon layer coating,enhanced Li+migration ability and structural stability induced by Mg doping,the Li(Fe_(0.4)Mn_(0.6))_(0.97)Mg_(0.03)PO_(4)/C exhibits splendid electrochemical performance.

Lewis acid-doped transition metal dichalcogenides for ultraviolet–visible photodetectors

Ultraviolet photodetectors(UV PDs)are widely used in civilian,scientific,and military fields due to their high sensitivity and low false alarm rates.We present a temperature-dependent Lewis acid p-type doping method for transition metal dichalcogenides(TMDs),which can effectively be used to extend the optical response range.The p-type doping based on surface charge transfer involves the chemical adsorption of the Lewis acid SnCl_(4)as a light absorption layer on the surface of WS_(2),significantly enhancing its UV photodetection performance.Under 365 nm laser irradiation,WS_(2)PDs exhibit response speed of 24 ms/20 ms,responsivity of 660 mA/W,detectivity of 3.3×10^(11)Jones,and external quantum efficiency of 226%.Moreover,we successfully apply this doping method to other TMDs materials(such as MoS_(2),MoSe_(2),and WSe_(2))and fabricate WS_(2) lateral p–n heterojunction PDs.

NaH doped TiO_(2)as a high-performance catalyst for Mg/MgH_(2)cycling stability and room temperature absorption

This paper presents the catalytic effect of NaH doped nanocrystalline TiO_(2)(designated as NaTiOxH)in the improvement of MgH_(2)hydrogen storage properties.The catalyst preparation involves ball milling NaH with TiO_(2)for 3 hr.The addition of 5 wt%NaTiOxH powder into MgH_(2)reduces its operating temperature to∼185℃,which is∼110℃lower than the additive-free as-milled MgH_(2).The composite remarkably desorbs∼7.2 wt%H_(2)within 15 min at∼290℃and reabsorbs∼4.5 wt%H_(2)in 45 min at room temperature under 50 bar H_(2).MgH_(2)dehydrogenation is activated at 57 kJ/mol by the catalyst.More importantly,the addition of 2.5 wt%NaTiOxH catalyst aids MgH_(2)to reversibly produce∼6.1 wt%H_(2)upon 100 cycles within 475 hr at 300℃.Microstructural investigation into the catalyzed MgH_(2)composite reveals a firm contact existing between NaTiOxH and MgH_(2)particles.Meanwhile,the NaTiOxH catalyst consists of catalytically active Ti_(3)O_(5),and“rod-like”Na_(2)Ti_(3)O_(7)species liberated in-situ during preparation;these active species could provide multiple hydrogen diffusion pathways for an improved MgH_(2)sorption process.Furthermore,the elemental characterization identifies the reduced valence states of titanium(Ti<4+)which show some sort of reversibility consistent with H_(2)insertion and removal.This phenomenon is believed to enhance the mobility of Mg/MgH_(2)electrons by the creation and elimination of oxygen vacancies in the defective(TiO_(2-x))catalyst.Our findings have therefore moved MgH_(2)closer to practical applications.

Preparation of Sn-doped Ga_(2)O_(3) thin films and their solar-blind photoelectric detection performance

Sn doping is an effective way to improve the response rate of Ga_(2)O_(3) film based solar-blind detectors. In this paper,Sn-doped Ga_(2)O_(3) films were prepared on a sapphire substrate by radio frequency magnetron sputtering. The films were characterized by X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy and ultraviolet visible spectroscopy, and the effect of annealing atmosphere on the properties of films was studied. The Ga_(2)O_(3) films changed from amorphous to β-Ga_(2)O_(3) after annealing at 900 °C. The films were composed of micro crystalline particles with a diameter of about 5–20 nm.The β-Ga_(2)O_(3) had high transmittance for wavelengths above 300 nm, and obvious absorption for solar-blind signals at 200–280 nm.The metal semiconductor metal type solar-blind detectors were prepared. The detector based on Sn-doped β-Ga_(2)O_(3) thin film annealed in N_2 has the best response performance to 254 nm light. The photo-current is 10 μA at 20 V, the dark-current is 5.76 pA,the photo dark current ratio is 1.7 × 10~6, the response rate is 12.47 A/W, the external quantum efficiency is 6.09 × 10~3%, the specific detection rate is 2.61 × 10~(12) Jones, the response time and recovery time are 378 and 90 ms, respectively.

Boost activation of peroxymonosulfate by iron doped K_(2-x)Mn_(8)O_(16):Mechanism and properties

Among the numerous transition metal catalysts,manganese-based compounds are considered as promising peroxymonosulfate(PMS)catalysts due to their low cost and environmental friendliness,such as cryptomelane manganese oxide(K_(2-x)Mn_(8)O_(16):abbreviation KMnO).However,the limited catalytic performance of KMnO limits its practical application.In this work,iron-doped KMnO(Fe-KMnO)was prepared by one-step hydrothermal method to optimize its catalytic performance.Compared with KMnO/PMS system,Fe-KMnO/PMS system possessed more excellent removal efficiency of tetracycline(TC).Meanwhile,the Fe-KMnO/PMS system also exhibited good practical application potential and excellent stability.The mechanism of Fe-KMnO activation of PMS was further analyzed in detail.It was found that Fe participated in the redox of high-valent Mn,which promoted the activation of PMS.Moreover,The Fe site as an adsorption site enhanced the TC enrichment ability of the catalyst,reducing the mass transfer resistance and further enhancing the TC removal ability of Fe-KMnO/PMS system.This work not only provides an excellent PMS catalyst,but also offers new insights into the mechanism of PMS activation by bimetallic manganese-based catalysts.

Structural, Optical and Photocatalytic Properties of Cu2+ Doped ZnO Nanorods with Using HMTA Solvent Prepared by Hydrothermal Method

In this experiment, Cu2+ doped ZnO (Cu-ZnO) nanorods materials have been fabricated by hydrothermal method. Cu2+ ions were doped into ZnO with ratios of 2, 5 and 7 mol.% (compared to the mole’s number of Zn2+). The hexamethylenetetramine (HMTA) solvent used for the fabrication of Cu-ZnO nanorods with the mole ratio of Zn2+:HMTA = 1:4. The characteristics of the materials were analyzed by techniques, such as XRD, Raman shift, SEM and UV-vis diffuse reflectance spectra (DRS). The photocatalytic properties of the materials were investigated by the decomposition of the methylene blue (MB) dye solution under ultraviolet light. The results show that the size of Cu-ZnO nanorods was reduced when the Cu2+ doping ratio increased from 2 mol.% to 7 mol.%. The decomposition efficiency of the MB dye solution reached 92% - 97%, corresponding to the Cu2+ doping ratio changed from 2 - 7 mol.% (after 40 minutes of ultraviolet irradiation). The highest efficiency for the decomposition of the MB solution was obtained at a Cu2+ doping ratio of 2 mol.%.

Microstructure and magnetic properties of Ni-Zn ferrites doped with MnO_2

To improve the performance of Ni-Zn ferrites for power field use,the influence of MnO2 additive on the properties of Ni-Zn ferrites was investigated by the conventional powder metallurgy.The results show that MnO2 does not form a visible second phase in the doping mass fraction range of（0-2.0%）.The average grain size,sintering density and real permeability gradually decrease with the increase of the MnO2 content.And the DC resistivity continuously increases with the increase of MnO2 content.The saturation magnetization（magnetic moment in unit mass） first increases slightly when mass fraction of MnO2 is less than 0.4% MnO2,and then gradually decreases with increasing the MnO2 mass fraction due to the exchange interaction of the cations.When the excitation frequency is less than 1 MHz,the power loss（Pcv） continuously increases with increasing the MnO2 content due to the decrease of average grain size.However,when the excitation frequency exceeds 1 MHz,eddy current loss gradually becomes the predominant contribution to Pcv.And the sample with a higher resistivity favors a lower Pcv,except for the sample with 2.0% MnO2.The sample without additive has the best Pcv when worked at frequencies less than 1 MHz;and the sample with 1.6% MnO2 additive has the best Pcv when worked at frequencies higher than 1 MHz.

5%Ag掺杂对MNO_(2)纳米棒和海胆微球形貌及其甲苯氧化性能的影响

采用水热法制备了MNO_(2)纳米棒和海胆微球,并原位掺杂5%Ag制备了Mn-Ag复合氧化物,利用SEM、XRD、BET、Raman等表征技术对其结构进行表征,并考察不同催化剂对甲苯的去除性能。结果表明:(NH_(4))_(2)S_(2)O_(8)的掺入量会对MNO_(2)的形貌产生影响,当其掺入量为2.28 g时,形成MNO_(2)纳米棒,当其掺入量为6.84 g时,形成MNO_(2)海胆微球;MNO_(2)纳米棒掺杂5%的Ag后,形貌未发生变化,但当MNO_(2)海胆微球掺杂5%Ag时,表面的纳米线较MNO_(2)海胆微球有所增长,且出现了缠绕现象,形成了空心鸟巢状结构;5%Ag掺杂后,对MNO_(2)纳米棒和MNO_(2)海胆微球的晶型未产生影响,均为α-MNO_(2),但5%Ag-MNO_(2)纳米棒出现了Mn2O_(3)的衍射峰;MNO_(2)海胆微球较MNO_(2)纳米棒的比表面积、孔径和孔容均增大,且Ag的掺杂进一步提高了MNO_(2)海胆微球的比表面积、孔径和孔容;MNO_(2)海胆微球比MNO_(2)纳米棒具有更好的甲苯去除性能,且5%Ag掺杂后,MNO_(2)海胆微球对甲苯的去除性能达到最好。

Al掺杂对SiO_(2)气凝胶耐高温特性的影响研究

SiO_(2)气凝胶具有成本低、制造工艺简单、化学性质稳定、密度小、超高比表面积等优点,是应用最广泛的高温保温隔热材料。以Si28和Si40为Si源,仲丁醇铝为Al源,乙醇为溶剂,采用酸碱催化、CO_(2)超临界干燥法制备了Al掺杂SiO_(2)气凝胶。结果表明:所得产品高温热处理后均为非晶态无定型结构,无掺杂SiO_(2)气凝胶线收缩率为24.34%,Al掺杂SiO_(2)气凝胶线收缩为14.05%,且在高温热处理后有较大的比表面积和孔体积,说明Al掺杂SiO_(2)气凝胶具有较好的耐高温性能和高温下的绝热性能,这是因为Al元素的掺入使气凝胶在形成过程中产生了很多细小的纳米空洞,热处理过程中Al-Si-O发生化学反应形成双金属氧化物,使气凝胶的氧化物骨架支撑力更强。

掺杂对2H-MoTe_(2)光电特性影响的第一性原理研究

MoTe_(2)是一种非空间反演对称性半导体,由线性偏振光照射,在无偏压条件下可以直接产生光电流,但是非常微弱.掺杂可以改变电子能带结构和降低空间反演对称性,从而有效的增强光电流.本文基于非平衡格林函数-密度泛函理论,采用第一性原理,计算了本征、Nb掺杂、Ti掺杂和W掺杂2H-MoTe_(2)的能带结构、透射谱和光电流.能带结构表明:Nb掺杂使半导体2H-MoTe_(2)能带穿越费米能级,转变为金属特性;Ti和W掺杂减小了2H-MoTe_(2)的带隙,能带没有穿越费米能级,依然为半导体.掺杂都降低2H-MoTe_(2)的反演对称对称性,从本征的D3h转变为Cs.从而在线偏振光的照射下可以有效的提高2H-MoTe_(2)的光电流.同时,发现掺杂可以提高单层2H-MoTe_(2)在低光子能量下的消光比,如Nb和Ti掺杂单层2H-MoTe_(2)分别在光子能量1.1 eV和1.2 eV处取得39.48和28.48的高消光比.这些结果表明掺杂可以有效增强单层2H-MoTe_(2)的光电流和消光比,可以应用于指导2H-MoTe_(2)在光电器件的设计,特别是在红外光探测领域增添了许多可能.

Preparation and photocatalytic performance of Cu-doped TiO_2 nanoparticles

Cu-doped TiO2 nanoparticles with different doping contents from 0 to 2.0% （mole fraction） were synthesized through sol-gel method. X-ray diffraction （XRD）, X-ray photoelectron spectroscopy （XPS） and field emission scanning electron microscope （FE-SEM） were used to characterize the crystalline structure, chemical valence states and morphology of TiO2 nanoparticles. UV-Vis absorption spectrum was used to measure the optical absorption property of the samples. The photocatalytic performance of the samples was characterized by degrading 20 mg/L methyl orange under UV-Vis irradiation. The results show that the Cu-doped TiO2 nanoparticles exhibit a significant increase in photocatalytic performance over the pure TiO2 nanoparticles, and the TiO2 nanoparticles doped with 1.0% Cu show the best photocatalytic performance. The improvement in photocatalytic performance is attributed to the enhanced light adsorption in UV-Vis range and the decrease of the recombination rate of photoinduced electron-hole oair of the Cu-doped TiO2 nanoparticles.

改性TiO_(2)在光电协同下处理偶氮染料废水的研究进展

偶氮染料(AZO)是一类难被生物降解的水溶性高分子有机物,近些年来,由于良好的染色性能被广泛应用于印染等相关行业,但AZO废水一旦排入自然水体将会造成重大的环境污染问题。本文主要介绍了不同类型的改性TiO_(2)对AOZ废水的处理效果并分析了作用原理,对比分析了单一TiO_(2)与改性TiO_(2)的优缺点,积极探索改性TiO_(2)催化剂的催化机理,解析金属和非金属掺杂在其中的具体作用,为今后更加精准地控制掺杂金属或者非金属比例、提高催化剂效率提供科学依据和技术支持。

Designing interstitial boron-doped tunnel-type vanadium dioxide cathode for enhancing zinc ion storage capability

Chemical doping is a powerful method to intrinsically tailor the electrochemical properties of electrode materials.Here,an interstitial boron-doped tunnel-type VO_(2)(B)is constructed via a facile hydrothermal method.Various analysis techniques demonstrate that boron resides in the interstitial site of VO_(2)(B)and such interstitial doping can boost the zinc storage kinetics and structural stability of VO_(2)(B)cathode during cycling.Interestingly,we found that the boron doping level has a saturation limit peculiarity as proved by the quantitative analysis.Notably,the 2 at.%boron-doped VO_(2)(B)shows enhanced zinc ion storage performance with a high storage capacity of 281.7 mAh g^(-1) at 0.1 A g^(-1),excellent rate performance of 142.2 mAh g^(-1) at 20 A g^(-1),and long cycle stability up to 1000 cycles with the capacity retention of 133.3 mAh g^(-1) at 5 A g^(-1).Additionally,the successful preparation of the boron-doped tunneltype α-MnO_(2) further indicates that the interstitial boron doping approach is a general strategy,which supplies a new chance to design other types of functional electrode materials for multivalence batteries.

过渡金属W、Mn、V、Ti掺杂二维材料MoSi_(2)N_(4)的第一性原理计算

本文基于密度泛函理论(DFT)的第一性原理计算了W、Mn、V、Ti替位掺杂二维MoSi_(2)N_(4)后的几何结构、电子结构以及光学性质的变化.电子结构分析表明W、Mn、W、Ti替位掺杂二维MoSi_(2)N_(4)后的禁带宽度分别为1.806 e V、1.003 e V、1.218 e V和1.373 e V;四种过渡金属掺杂后MoSi_(2)N_(4)的带隙类型没有发生改变,均为间接带隙半导体;W掺杂后的杂质能级靠近价带顶,费米能级靠近价带顶,为p型半导体,杂质能级为受主能级;Mn掺杂后的杂质能级靠近导带底,费米能级靠近导带底,为n型半导体;V和Ti掺杂后杂质能级位于费米能级附近,为复合中心;光学性质分析表明,在2 e V~4 e V的能量区间内,W掺杂结构的吸收波长为336 nm,体系发生红移;Mn、V和Ti替位掺杂后的吸收波长分别为320 nm、358 nm和338 nm,且掺杂体系均发生蓝移.