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Structurally Flexible 2D Spacer for Suppressing the Electron-Phonon Coupling Induced Non-Radiative Decay in Perovskite Solar Cells
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作者 Ruikun Cao Kexuan Sun +8 位作者 Chang Liu Yuhong Mao Wei Guo Ping Ouyang Yuanyuan Meng Ruijia Tian Lisha Xie Xujie Lü Ziyi Ge 《Nano-Micro Letters》 SCIE EI CAS CSCD 2024年第9期325-340,共16页
This study presents experimental evidence of the dependence of non-radiative recombination processes on the electron-phonon coupling of perovskite in perovskite solar cells(PSCs).Via A-site cation engineering,a weaker... This study presents experimental evidence of the dependence of non-radiative recombination processes on the electron-phonon coupling of perovskite in perovskite solar cells(PSCs).Via A-site cation engineering,a weaker electron-phonon coupling in perovskite has been achieved by introducing the structurally soft cyclohexane methylamine(CMA^(+))cation,which could serve as a damper to alleviate the mechanical stress caused by lattice oscillations,compared to the rigid phenethyl methylamine(PEA^(+))analog.It demonstrates a significantly lower non-radiative recombination rate,even though the two types of bulky cations have similar chemical passivation effects on perovskite,which might be explained by the suppressed carrier capture process and improved lattice geometry relaxation.The resulting PSCs achieve an exceptional power conversion efficiency(PCE)of 25.5%with a record-high opencircuit voltage(V_(OC))of 1.20 V for narrow bandgap perovskite(FAPbI_(3)).The established correlations between electron-phonon coupling and non-radiative decay provide design and screening criteria for more effective passivators for highly efficient PSCs approaching the Shockley-Queisser limit. 展开更多
关键词 Electron-phonon coupling A-site cation engineering non-radiative recombination
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Temperature-Dependent Photoluminescence Analysis of 1.0 MeV Electron Irradiation-Induced Nonradiative Recombination Centers in n+-p GaAs Middle Cell of GaInP/GaAs/Ge Triple-Junction Solar Cells 被引量:1
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作者 王君玲 易天成 +2 位作者 郑勇 吴锐 王荣 《Chinese Physics Letters》 SCIE CAS CSCD 2017年第7期182-184,共3页
The effects of irradiation of 1.0 MeV electrons on the n+-p GaAs middle cell of GalnP/GaAs/Ge triple-junction solar cells are investigated by temperature-dependent photoluminescence (PL) measurements in the 10-300K... The effects of irradiation of 1.0 MeV electrons on the n+-p GaAs middle cell of GalnP/GaAs/Ge triple-junction solar cells are investigated by temperature-dependent photoluminescence (PL) measurements in the 10-300K temperature range. The appearance of thermal quenching of the PL intensity with increasing temperature confirms the presence of a nonradiative recombination center in the cell after the electron irradiation, and the thermal activation energy of the center is determined using the Arrhenius plot of the PL intensity. Furthermore, by comparing the thermal activation and the ionization energies of the defects, the nonradiative recombination center in the n+ p GaAs middle cell acting as a primary defect is identified as the E5 electron trap located at Ec - 0.96 eV. 展开更多
关键词 Temperature-Dependent Photoluminescence Analysis of 1.0 MeV Electron Irradiation-Induced Nonradiative recombination centers in n Ge
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Features of Recombination Radiation of GaAs Type Semiconductors with the Participation of Fine Acceptor Levels in a Magnetic Field
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作者 Nosirjon Khaydarovich Yuldashev Iftixorjon Isaqovich Yulchiev +1 位作者 Bozorboy Joboraliyevich Akhmadaliev Khusanboy Manopovich Sulaymonov 《Journal of Applied Mathematics and Physics》 2024年第7期2407-2420,共14页
Using the method of Picus and Beer invariants, general expressions are obtained for the total intensity I and the degree of circular polarization Рcirc.of the luminescence of GaAs-type semiconductors with the partici... Using the method of Picus and Beer invariants, general expressions are obtained for the total intensity I and the degree of circular polarization Рcirc.of the luminescence of GaAs-type semiconductors with the participation of shallow acceptor levels in a longitudinal magnetic field H. Special cases are analyzed depending on the value and direction of the magnetic field strength, as well as on the constants of the g-factor of the acceptor g1,g2and the conduction band electron ge. In the case of a strong magnetic field H// [100], [111], [110], a numerical calculation of the angular dependence of the quantities I and Рcirc.was performed for some critical values of g2/g1, at which Рcirc.exhibits a sharp anisotropy in the range from −100% to +100%, and the intensity of the crystal radiation along the magnetic field tends to a minimum value. 展开更多
关键词 Semiconductor recombination Radiation Shallow Acceptor center Magnetic Field Zeeman Splitting G-FACTORS Anisotropy Circular Polarization Intensity
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Study of Nonradiative Recombination Centers in n-GaN Grown on LT-GaN and AlN Buffer Layer by Below-Gap Excitation
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作者 M. D. Haque M. Julkarnain +1 位作者 A. Z. M. Touhidul Islam N. Kamata 《Advances in Materials Physics and Chemistry》 2018年第3期143-155,共13页
Nonradiative recombination (NRR) centers in n-type GaN samples grown by MOCVD technique on a LT-GaN buffer layer and aAlN buffer layer have been studied by two wavelength excited photoluminescence (TWEPL). The near ba... Nonradiative recombination (NRR) centers in n-type GaN samples grown by MOCVD technique on a LT-GaN buffer layer and aAlN buffer layer have been studied by two wavelength excited photoluminescence (TWEPL). The near band-edge photoluminescence (PL) intensity decreases due to the superposition of below-gap excitation (BGE) light of energies 0.93, 1.17 and 1.27 eV over above-gap excitation (AGE) light of energy 4.66 eV. The decrease in PL intensity due to the addition of the BGE has been explained by a two levels recombination model based on SRH statistics. It indicates the presence of a pair of NRR centers in both samples, which are activated by the BGE. The degree of quenching in PL intensity for the sample grown on LT-GaN buffer layer is stronger than the sample grown on AlN buffer layer for all BGE sources. This result implies that the use of the AlN buffer layer is more effective for reducing the NRR centers in n-GaN layers than the LT-GaN buffer layer. The dependence of PL quenching on the AGE density, the BGE density and temperature has been also investigated. The NRR parameters have been quantitatively determined by solving rate equations and fitting the simulated results with the experimental data. 展开更多
关键词 N-TYPE GAN Two-Wavelength EXCITED PHOTOLUMINESCENCE Nonradiative recombination center recombination Model
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Influence of Recombination Centers on the Phase Portraits in Nanosized Semiconductor Films
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作者 Gafur Gulyamov Abdurasul G. Gulyamov Feruza R. Muhitdinova 《Journal of Modern Physics》 2016年第13期1661-1667,共8页
Influence of recombination centers’ changes on the form of phase portraits has been studied. It has been shown that the shape of the phase portraits depends on the concentration of semiconductor materials’ recombina... Influence of recombination centers’ changes on the form of phase portraits has been studied. It has been shown that the shape of the phase portraits depends on the concentration of semiconductor materials’ recombination centers. 展开更多
关键词 recombination centers Phase Portrait Generation of Charge Carriers recombination of Charge Carriers Forbidden Zone Absorption Coefficient
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Charge Localization Induced by Reorientation of FA Cations Greatly Suppresses Nonradiative Electron-Hole Recombination in FAPbI3 Perovskites:a Time-Domain Ab Initio Study
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作者 Jin-lu He Yong-hao Zhu Run Long 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2020年第5期642-648,I0079,共8页
Recent experiments report the rotation of FA(FA=HC[NH2]2+)cations significantly influence the excited-state lifetime of FAPbI3.However,the underlying mechanism remains unclear.Using ab initio nonadiabatic(NA)molecular... Recent experiments report the rotation of FA(FA=HC[NH2]2+)cations significantly influence the excited-state lifetime of FAPbI3.However,the underlying mechanism remains unclear.Using ab initio nonadiabatic(NA)molecular dynamics combined with time-domain density functional simulations,we have demonstrated that reorientation of partial FA cations significantly inhibits nonradiative electron-hole recombination with respect to the pristine FAPbI3 due to the decreased NA coupling by localizing electron and hole in different positions and the suppressed atomic motions.Slow nuclear motions simultaneously increase the decoherence time,which is overcome by the reduced NA coupling,extending electron-hole recombination time scales to several nanoseconds and being about 3.9 times longer than that in pristine FAPbI3,which occurs within sub-nanosecond and agrees with experiment.Our study established the mechanism for the experimentally reported prolonged excited-state lifetime,providing a rational strategy for design of high performance of perovskite solar cells and optoelectronic devices. 展开更多
关键词 Hybrid organic-inorganic perovskite Localized charge non-radiative electronhole recombination Nonadiabatic molecular dynamics Time-dependent density functional theory
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Unveiling non-radiative center control in CsPbBr_(3) nanocrystals:A comprehensive comparative analysis of hot injection and ligandassisted reprecipitation approaches
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作者 Daocheng Hong Yuchen Zhang +9 位作者 Shuhan Pan Hanyu Liu Wei Mao Wanli Zhang Yuhui Ye Zhihong Wei Xuxing Lu Xiaoyong Wang Zhenda Lu Yuxi Tian 《Nano Research》 SCIE EI CSCD 2024年第5期4525-4534,共10页
Metal-halide perovskite nanocrystals(NCs)have gained significant attention in the field of optoelectronic and photonic devices due to their promising applications.Despite their exceptional optical properties,the impac... Metal-halide perovskite nanocrystals(NCs)have gained significant attention in the field of optoelectronic and photonic devices due to their promising applications.Despite their exceptional optical properties,the impact of different synthetic strategies on the fundamental nature of NCs,such as nonradiative recombination centers,remains poorly understood.In this study,we investigated the photophysical properties of CsPbBr_(3) NCs synthesized using two distinct methods,hot injection and ligand-assisted reprecipitation,at the individual particle level.We observed different blinking behaviors under specific photoexcitation power densities and proposed,through intensity-lifetime analysis and Monte-Carlo simulations,that these different synthetic strategies can fabricate NCs with similar crystal structures but distinct surface quenchers with varying energy levels,which significantly affected the photo-induced blinking-down and blinking-up behaviors in individual NCs.Our findings indicate a practical and feasible approach for controlling defect engineering in perovskite NCs,with significant implications for their use in optoelectronic and other technological applications. 展开更多
关键词 metal-halide perovskite nanocrystals photophysical properties nonradiative recombination centers hot injection method ligand-assisted reprecipitation
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Achieving improved stability and minimal non-radiative recombination loss for over 18%binary organic photovoltaics via versatile interfacial regulation strategy
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作者 Lifu Zhang Houdong Mao +4 位作者 Liqiang Huang Lei Hu Xinkang Wang Licheng Tan Yiwang Chen 《Science China Chemistry》 SCIE EI CAS CSCD 2022年第8期1623-1633,共11页
Interfacial regulation,serving multiple roles,is critical for the fabrication of stable and efficient organic photovoltaics(OPVs).Herein,a multifunctional cathode interlayer PDINO(15 nm)is prepared by regulating film ... Interfacial regulation,serving multiple roles,is critical for the fabrication of stable and efficient organic photovoltaics(OPVs).Herein,a multifunctional cathode interlayer PDINO(15 nm)is prepared by regulating film thickness,which is inserted between active components and stable silver electrode to align work function,and maintain good interfacial contact and device stability.The thick film can help to reduce interfacial surface defects,keep stable surface morphology,and block the silver diffusion into the active layer.Consequently,the optimal PM6:Y6 device records an impressive power conversion efficiency(PCE)of 17.48%with minimized non-radiative recombination loss of 0.239 V.More importantly,the unencapsulated device maintains 91%of the original PCE after aging for over 60 days at 25℃ and 10%relative humidity in dark conditions.Meanwhile,the PM6:eC9 device achieves a remarkable PCE of 18.22%with the enhancement of open-circuit voltage(V_(oc)).Furthermore,the 1 cm^(2) device-based PDINO(15 nm)/Ag shows a high PCE of 15.2%while only 12.6%for PDINO(9 nm)/Al,indicating the good compatibility of PDINO(15 nm)interlayer with the R2R coating processes used in large-area OPVs fabrication.This work highlights the promise of interfacial regulation to simultaneously stabilize and enhance the efficiency of organic photovoltaics. 展开更多
关键词 organic photovoltaics interfacial regulation device stability non-radiative recombination loss high performance
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双芯IGCT浪涌电流鲁棒性研究 被引量:1
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作者 鲁一苇 姚德贵 +3 位作者 董曼玲 肖超 陈涛 杨武华 《半导体技术》 CAS 北大核心 2024年第3期234-239,245,共7页
作为晶闸管类器件,双芯集成门极换流晶闸管(Dual IGCT)必须具备的抗浪涌电流能力研究鲜见报道。基于多单元集成的器件仿真结构模型,揭示了Dual IGCT在浪涌电流下工作时,总电流在GCT-A部分和GCT-B部分间的分配比例会随晶格温度升高而减... 作为晶闸管类器件,双芯集成门极换流晶闸管(Dual IGCT)必须具备的抗浪涌电流能力研究鲜见报道。基于多单元集成的器件仿真结构模型,揭示了Dual IGCT在浪涌电流下工作时,总电流在GCT-A部分和GCT-B部分间的分配比例会随晶格温度升高而减小。在此基础上,分析了寿命控制技术对Dual IGCT浪涌鲁棒性的影响。结果表明,增大GCT-B的载流子寿命可以提高器件的浪涌鲁棒性,但同时会增大器件的功耗;而在对GCT-B进行载流子寿命控制时,引入具有较大寿命对温度依赖系数的复合中心,可以有效提高Dual IGCT浪涌电流鲁棒性,同时不影响器件的其他性能。最后,提出了一种工艺成本较低的阳极短路Dual IGCT新结构,其在浪涌电流下的晶格温升与传统的Dual IGCT相比大幅减小(约150 K),呈现出极高的抗浪涌能力。 展开更多
关键词 双芯集成门极换流晶闸管(Dual IGCT) 浪涌电流 寿命控制 复合中心 鲁棒性
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Minimizing interfacial energy losses in inverted perovskite solar cells by a dipolar stereochemical 2D perovskite interface
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作者 Junjie Qian Jingjing He +10 位作者 Qihang Zhang Chenyue Zhu Shilin Chen Zhanpeng Wei Xuesong Leng Ziren Zhou Benben Shen Yu Peng Qiang Niu Shuang Yang Yu Hou 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第3期496-503,I0011,共9页
Inverted perovskite solar cells(PSCs) have attracted broad research and industrial interest owing to their suppressed hysteresis,cost-effectiveness,and easy-fabrication.However,the issue of non-radiative recombination... Inverted perovskite solar cells(PSCs) have attracted broad research and industrial interest owing to their suppressed hysteresis,cost-effectiveness,and easy-fabrication.However,the issue of non-radiative recombination losses at the n-type interface between the perovskite and fullerene has impeded further improvement of photovoltaic performance.Here,we modify the n-type interface of FAPbI_(3) perovskite films by constructing a stereochemical two-dimensional(2D) perovskite interlayer,in which the organic cations comprise both pyridine and ammonium groups.The pyridine N donor can create stable bonding with the surface-uncoordinated Pb on the perovskite,thereby passivating the shallow-level defects and enhancing the air stability of the film.Furthermore,the pyridine N donor also offers a positive polar interface to decrease the surface work function of the perovskite film,enabling n-type modification.Ultimately,we employ a p-i-n photovoltaic(PV) device with the positive dipole interlayer at perovskite/fullerene contact and achieve remarkable photoelectric conversion efficiency(PCE) of 22.0%. 展开更多
关键词 Perovskite solar cells Dipole interlayer STEREOCHEMISTRY non-radiative recombination
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Influence of surface passivation on the minority carrier lifetime, Fe-B pair density and recombination center concentration 被引量:2
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作者 LI Feng MA ZhongQuan +3 位作者 MENG XiaJie LU Peng YU ZhengShan HE Bo 《Chinese Science Bulletin》 SCIE EI CAS 2010年第17期1828-1833,共6页
Three kinds of methods (0.08 mol/L iodine in ethanol, SiNx:H, and 40% HF) are used to passivate solar-grade Czochralski (Cz) silicon wafers. Thereafter, minority carrier lifetime and Fe-B pair density of the wafers ar... Three kinds of methods (0.08 mol/L iodine in ethanol, SiNx:H, and 40% HF) are used to passivate solar-grade Czochralski (Cz) silicon wafers. Thereafter, minority carrier lifetime and Fe-B pair density of the wafers are measured using the microwave photo-conductance decay (μ-PCD) technique. Based on the measured minority carrier lifetime, it is found that the passivation quality achieved by 0.08 mol/L iodine in ethanol is the best, while that by 40% HF solution is the worst. For the identical wafer, the density distribution of Fe-B pairs is different when different passivation methods are used. When the wafers are passivated by SiNx:H, there exists a close correlation between the distribution of minority carrier lifetime and the concentration distribution of Fe-B pairs. Furthermore, for wafers with high-quality passivation, there is a strong correlation between the recombination center concentration and the Fe-B pair density. All the analyses verify that the surface passivation quality of wafers influences the measurement results of minority carrier lifetime, Fe-B pair density and recombination center concentration. 展开更多
关键词 少数载流子寿命 表面钝化 密度分布 复合中心 浓度分布 少子寿命
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平面工艺辐射探测器的研制 被引量:3
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作者 张太平 张录 +6 位作者 宁宝俊 田大宇 刘诗美 王玮 张洁天 郭昭乔 陈世媛 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2001年第3期354-357,共4页
使用高阻 Si材料 ,通过氧化、光刻、注入和退火工艺技术研制粒子探测器—— PIN二极管 .采取 HCl氧化、慢降温等工艺措施可减小 PIN二极管的暗电流 (反向电流 ) ,这对于提高器件性能起到了关键作用 .电压为 - 5 V时 ,探测器的暗电流可达... 使用高阻 Si材料 ,通过氧化、光刻、注入和退火工艺技术研制粒子探测器—— PIN二极管 .采取 HCl氧化、慢降温等工艺措施可减小 PIN二极管的暗电流 (反向电流 ) ,这对于提高器件性能起到了关键作用 .电压为 - 5 V时 ,探测器的暗电流可达 n A/ cm2 量级 . 展开更多
关键词 PIN二极管 少子寿命 平面工艺 辐射探测器
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重组人血小板生成素治疗肿瘤患者化疗后血小板减少症的疗效和安全性:Ⅱ/Ⅲ期及补充多中心随机对照临床试验的汇总分析 被引量:17
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作者 吴全睿 赵永强 +33 位作者 储大同 徐兵河 廖美琳 姜丽岩 徐建民 王华英 李进 侯梅 周清华 张力建 张树才 夏忠军 姜文奇 吕跃 翟明 孟凡义 王东星 王健民 陈正堂 关华军 王庆余 陈协群 刘基巍 张阳 宋善俊 刘文励 于世英 徐建明 宋恕平 徐健 李丽庆 张梅 孙红 江滨 《中国肿瘤生物治疗杂志》 CAS CSCD 北大核心 2013年第6期645-653,共9页
目的:汇总Ⅱ/Ⅲ期和补充多中心临床试验资料,评价重组人血小板生成素(recombinant human thrombopoietin,rh-TPO)治疗实体肿瘤患者化疗后血小板(platelet,PLT)减少症的临床疗效和安全性。方法:3个试验共入组受试者276例,其中Ⅱ期试验入... 目的:汇总Ⅱ/Ⅲ期和补充多中心临床试验资料,评价重组人血小板生成素(recombinant human thrombopoietin,rh-TPO)治疗实体肿瘤患者化疗后血小板(platelet,PLT)减少症的临床疗效和安全性。方法:3个试验共入组受试者276例,其中Ⅱ期试验入组63例,Ⅲ期试验入组154例,补充临床试验入组59例;其后剔除5例、脱落41例,共有230例纳入符合方案(pre-protocol,PP)数据集;所有患者均经组织学或细胞学证实患有实体肿瘤。Ⅱ期临床试验和补充临床试验为随机交叉自身对照试验,Ⅲ期临床试验中受试者按是否参加随机交叉对照分为随机交叉自身对照试验部分和非随机交叉自身对照部分。将接受rh-TPO用药的试验周期定义为用药周期,未用rh-TPO的周期定义为空白对照周期,试验期间的化疗方案和剂量均维持不变。将所有临床试验数据合并并进行疗效和安全性分析。结果:意向性治疗人群(intention-to-treat,ITT)数据集及PP数据集均显示出非常显著的一致性变化(以ITT集数据为例)。与对照周期相比,rh-TPO治疗可显著减轻化疗对PLT损伤的程度[化疗后PLT下降的最低值:(63.02±46.48)×109vs(49.47±31.41)×109个/L,P=0.002],缩短损伤和恢复时间[恢复至75×109个/L以上需要的天数:(11.18±9.71)vs(17.8±10.46)d,P=0.000],大幅提高血小板恢复水平[末次随访时PLT检测值:(211.21±119.20)×109vs(138.13±71.54)×109个/L,P=0.000;化疗后PLT最高值:(262.78±162.60)×109vs(149.36±73.26)×109个/L,P=0.000;末次随访时PLT与基线的差值:(79.64±118.06)×109vs(-8.92±102.50)×109个/L,P=0.000]。rh-TPO还可降低PLT输注患者的比例(12.21%vs 19.85%,P=0.017),减少PLT输注例次(0.22±0.72)vs(0.37±0.90)次,P=0.010)和输注量[(1.66±6.09)vs(2.77±7.08)U,P=0.009];补充试验中,PLT输注患者比例减少更为显著(13.79%vs 33.93%,P=0.0082)。用药前后血红蛋白含量和白细胞计数变化、肝肾功能、凝血功能的差异均无统计学意义(P>0.05)。276例患者中仅出现11例次不良反应,多为发热(6例)或寒战(2例)。结论:实体肿瘤患者化疗后给予国产rh-TPO可显著减轻化疗对PLT的损伤程度,缩短损伤和恢复时间,大幅提高PLT水平,降低患者PLT输注的例次和数量,且无严重不良反应。 展开更多
关键词 重组人血小板生成素 实体肿瘤 化疗 血小板减少症 随机对照试验 自身交叉 多中心临床试验 疗效 安全性
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用局域寿命控制技术改善功率快恢复二极管性能的仿真研究 被引量:4
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作者 吴鹤 吴郁 +1 位作者 亢宝位 贾云鹏 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2003年第5期520-527,共8页
针对局域低寿命区的参数对快恢复硅功率二极管性能的影响进行了系统的仿真研究 ,得到了全面系统的研究结果 ,其中包括局域低寿命区在二极管中的位置不同和局域低寿命区中复合中心能级在禁带中的位置不同对快恢复二极管的反向恢复时间 ( ... 针对局域低寿命区的参数对快恢复硅功率二极管性能的影响进行了系统的仿真研究 ,得到了全面系统的研究结果 ,其中包括局域低寿命区在二极管中的位置不同和局域低寿命区中复合中心能级在禁带中的位置不同对快恢复二极管的反向恢复时间 ( trr)、反向恢复软度因子 ( S)、正向压降 ( VF)、漏电流 ( IR)等各个单项性能的影响 ,以及对 trr- S、trr- VF 和 trr- IR 等各项性能综合折衷的影响 .这些结果对高速功率器件寿命工程研究和器件制造工程都有重要的参考价值 . 展开更多
关键词 局域寿命控制 快恢复硅功率二极管 参数折衷 轴向位置 复合中心能级位置
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采用选择激发研究光系统Ⅱ反应中心β-Car的物理特性(英文) 被引量:1
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作者 贺俊芳 王水才 +4 位作者 蔡霞 刘晓 彭菊芳 董凤琴 匡廷云 《光子学报》 EI CAS CSCD 北大核心 2004年第10期1187-1191,共5页
光系统Ⅱ反应中心包含有 2个去镁叶绿素分子 (Pheo) ,2个 β胡萝卜素分子 (β Car)和 6个叶绿素a分子 (Chla) 对反应中心的时间分辨荧光光谱表明 ,两个β Car具有不同的吸收光谱 ,吸收峰分别为 4 89nm(Car4 89)和 5 0 7nm(Car5 0 7) ,C... 光系统Ⅱ反应中心包含有 2个去镁叶绿素分子 (Pheo) ,2个 β胡萝卜素分子 (β Car)和 6个叶绿素a分子 (Chla) 对反应中心的时间分辨荧光光谱表明 ,两个β Car具有不同的吸收光谱 ,吸收峰分别为 4 89nm(Car4 89)和 5 0 7nm(Car5 0 7) ,Car4 89靠近吸收峰为 6 6 7nm和 6 75nm的叶绿素a(Chla) ,它的主要功能是保护反应中心免受单态氧的破坏 ,而不能将激发能传递给光化学反应活性的色素分子P6 80 ;Car5 0 7靠近吸收峰为 6 6 9nm的Chla分子 ;能够将激发能传递给P6 80 ,进行电荷分离 采用全局优化拟合的方法对荧光光谱进行处理 ,Car4 89在 6 1ps时间内将能量传递给Chla6 72 ,随后传给Chla6 77,处于激发态的Chla6 77在 3ns衰减到基态 ;Car5 0 7在 2 74ps时间内将能量传递给P6 80 ,P6 80 + Pheo- 的电荷重组发生在 3.8ns和 展开更多
关键词 光系统Ⅱ 反应中心 β-Car 电荷重组 能量传递
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氮化镓材料中的位错对材料物理性能的影响 被引量:5
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作者 倪贤锋 叶志镇 《材料导报》 EI CAS CSCD 2003年第11期9-12,共4页
氮化镓材料中的位错是制约GaN发光器件及电子器件的性能的一个关键因素。目前对于氮化镓材料中的位错的研究是一大热点。扼要综述了位错对于材料及器件的物理性能的影响:非辐射复合作用、造成器件的漏电流、缩短器件的寿命。并简要介绍... 氮化镓材料中的位错是制约GaN发光器件及电子器件的性能的一个关键因素。目前对于氮化镓材料中的位错的研究是一大热点。扼要综述了位错对于材料及器件的物理性能的影响:非辐射复合作用、造成器件的漏电流、缩短器件的寿命。并简要介绍了减少GaN外延层中的位错密度的几种方法。 展开更多
关键词 氮化镓材料 物理性能 位错 GAN 半导体材料
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曝光强度对卤化银微晶中载流子行为及其陷阱效应的影响 被引量:3
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作者 傅广生 刘荣鹃 +3 位作者 杨少鹏 江晓利 代秀红 李晓苇 《感光科学与光化学》 EI CSCD 2005年第1期21-28,共8页
针对卤化银感光材料潜影形成过程中光作用动力学问题,分析了曝光强度对光生载流子行为和电子陷阱效应的影响,认为伴随着曝光强度的增加,影响光电子衰减的因素由电子陷阱起主要作用演化到电子陷阱和复合中心共同起作用进而演化到复合中... 针对卤化银感光材料潜影形成过程中光作用动力学问题,分析了曝光强度对光生载流子行为和电子陷阱效应的影响,认为伴随着曝光强度的增加,影响光电子衰减的因素由电子陷阱起主要作用演化到电子陷阱和复合中心共同起作用进而演化到复合中心起主要作用. 展开更多
关键词 电子陷阱 复合中心 曝光强度 光电子 光空穴 卤化银
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LPCVD自组织生长Si纳米量子点的发光机制分析 被引量:2
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作者 彭英才 稻毛信弥 +1 位作者 池田弥央 宫崎诚一 《发光学报》 EI CAS CSCD 北大核心 2002年第3期261-264,共4页
采用低压化学气相沉积 (LPCVD)方法 ,通过纯SiH4气体的表面热分解反应 ,在SiO2 表面上自组织生长了半球状Si纳米量子点 ,在室温条件下实验研究了其光致发光 (PL)特性 ,考察了PL效率与峰值能量随Si纳米量子点尺寸的变化关系。结果指出 ,... 采用低压化学气相沉积 (LPCVD)方法 ,通过纯SiH4气体的表面热分解反应 ,在SiO2 表面上自组织生长了半球状Si纳米量子点 ,在室温条件下实验研究了其光致发光 (PL)特性 ,考察了PL效率与峰值能量随Si纳米量子点尺寸的变化关系。结果指出 ,当Si纳米量子点高度hc<5nm时 ,其PL效率基本保持不变。而当hc>5nm时 ,PL效率则急剧下降。同时 ,PL峰值能量随hc 的减少而增大 ,并与 (l/hc) 2 成正比依赖关系。如当hc 从 5 5nm减小至 0 8nm时 ,其峰值能量从 1 2 8eV增加到 1 4 3eV ,出现了约 0 15eV的谱峰蓝移。我们用量子限制效应 展开更多
关键词 LPCVD 自组织生长 发光机制 Si纳米量子点 量子限制效应-界面中心复合发光 低压化学气相沉积
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受主型杂质对p型单晶硅中少子衰减过程的影响 被引量:3
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作者 赵洋 王泽来 +4 位作者 张鹏 陆晓东 吴元庆 张宇峰 周涛 《半导体技术》 CAS CSCD 北大核心 2015年第12期930-936,共7页
少子寿命测试技术是监控单晶硅中杂质和缺陷的数量及性质的重要技术手段。基于常规光电导少子寿命测试的基本参数,研究了不同性质的受主型杂质缺陷对太阳电池用p型单晶硅中少子衰减过程的影响,并重点分析了仅存在受主型电子陷阱或复合... 少子寿命测试技术是监控单晶硅中杂质和缺陷的数量及性质的重要技术手段。基于常规光电导少子寿命测试的基本参数,研究了不同性质的受主型杂质缺陷对太阳电池用p型单晶硅中少子衰减过程的影响,并重点分析了仅存在受主型电子陷阱或复合中心时,少子衰减过程的变化规律;受主型电子陷阱和复合中心并存时,少子衰减过程的变化规律。研究表明:p型单晶硅中仅存在电子陷阱或复合中心时,二者的密度和俘获截面越小,少子寿命越长,且二者均存在一个最小阈值;当二者并存时,少子电子的衰减过程可根据少子寿命值的不同分成不同的衰减区域。 展开更多
关键词 p型单晶硅 少子寿命 电子陷阱 复合中心 杂质和缺陷密度 俘获截面
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基于单亲遗传模拟退火算法的顶点p-中心问题 被引量:4
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作者 蒋建林 徐进澎 文杰 《系统工程学报》 CSCD 北大核心 2011年第3期414-420,共7页
针对顶点p-中心问题这一经典的离散选址NP困难问题提出了一种单亲遗传和模拟退火的混合算法,该算法:1)采用单亲遗传算法简化遗传操作过程;2)加入模拟退火策略,增强局部优化能力;3)提出自适应选择法,根据个体的优劣及算法迭代情况来选择... 针对顶点p-中心问题这一经典的离散选址NP困难问题提出了一种单亲遗传和模拟退火的混合算法,该算法:1)采用单亲遗传算法简化遗传操作过程;2)加入模拟退火策略,增强局部优化能力;3)提出自适应选择法,根据个体的优劣及算法迭代情况来选择个体;4)设计了自适应基因重组操作;5)采取最优保存策略,避免最优解的丢失.数值实验结果表明了该算法对于解决规模较大的顶点p-中心问题的有效性. 展开更多
关键词 顶点p-中心问题 单亲遗传算法 模拟退火算法 自适应基因重组 自适应选择 混合算法
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