Studies of Luminescent Properties for InGaAsN Quantum Wells

针对InGaAsP/InP1.3-1.55μm长波长激光器具有温度特性差的缺点，近年来提出了InGaAsN/GaAs新型结构材料。它可以用于制造高性能的长波长垂直腔面发射激光器(VCSEL)。因此，近年来InGaAsN材料成为长波长光电器件的一个重要研究课题。 本文通过高分辨率X-射线衍射(HRXRD)实验与拟合得到In的组分和量子阱的阱宽。结合理论计算对光致发光(PL)谱中InGaAs和InGaAsN量子阱的11H发光峰进行指认，并拟合得到样品中N的组分，理论与实验结果吻合得相当好。比较样品的变温PL谱发现，在InGaAs中掺入少量的N可以使发光波长明显红移，而且适当提高N的组分有利于提高...InGaAsP/InP long-wavelength semiconductor lasers in 1.3-1.55μm wavelength has a disadvantage of relatively poor temperature characteristics. Recently, InGaAsN/GaAs system is proposed to solve the problem as a long wavelength material. Most attractive is the realization of long wavelength vertical cavity surface emitting laser (VCSEL) with high performance using InGaAsN/GaAs. Therefore, InGaAsN mat...学位：理学硕士院系专业：物理与机电工程学院物理学系_凝聚态物理学号：20012403

基于双岛结构的多晶硅纳米薄膜压力传感器

为解决传统半导体压力传感器温度特性差、非线性度高等问题,设计一种基于双岛结构的多晶硅纳米薄膜压力传感器。利用有限元分析软件分析硅膜结构的应力分布规律,确定力敏电阻的最佳布局,进一步提高了传感器的灵敏度。这种压力传感器兼具温度特性好、灵敏度高、线性度好等综合性能。福建省科技厅引导性(重点)项目(2017H032);;莆田学院激光精密加工工程技术研究中心开放基金项目(2016JZA014

Photoluminescence Spectroscopy Studies of InGaAsN Quantum Wells

我们测量了低N组分的InGaAsN/InGaAs/GaAs量子阱材料的光致发光(PL)谱,测量温度范围从13K到300K。实验结果显示,InGaAsN的PL谱的主峰值的能量位置随温度的变化呈现出反常的S型温度依赖关系。用Varshni经验公式对实验数据进行拟合之后,发现在低温下InGaAsN量子阱中的载流子是处于局域态的。此外,我们还测量了样品在不同的温度、不同的能量位置的瞬态谱,结果进一步证实了:在低温下,InGaAsN的PL谱谱峰主要是局域态激子的复合发光占据主导地位,而且InGaAsN中的载流子局域态主要是由N等电子缺陷造成的涨落势引起的。The photoluminescence (PL) spectroscopy in InGaAsN/InGaAs/GaAs quantum wells (QWs) with low-nitrogen composition has been measured in the temperature range 13-300K. The peak position energies of InGaAsN as measured by PL exhibit anomalous inverted S-shape-like temperature dependence. Fitting with Varshni empirical relation to PL data, we have found that carriers in InGaAsN QWs are localized at low temperatures. Moreover, Time-resolved photoluminescence (TRPL) measurements, performed for various temperatures and different PL energy position, further proved that the broad PL emission of InGaAsN at low temperature is mainly dominated by strong localization, which arises from nitrogen-induced fluctuating potential in quantum wells

Spectral Study of InGaAs/GaAs Strained Quantum Wells

【中文摘要】 分别用光致发光谱(PL)、光伏谱(PV)及时间分辨谱(TRPL)的方法,测量了应变InGaAs/GaAs单量子阱和多量子阱在不同温度下的光谱,发现单量子阱与多量子阱有不同的光学性质。多量子阱PL谱发光峰和PV谱激子峰的强度与半高宽都比单量子阱的大,但单量子阱的半高宽随着温度的升高增大很快,这是由激子 声子耦合引起的。通过时间分辨谱研究发现了量子阱子能级之间的跃迁,多量子阱的发光寿命明显比单量子阱的长。我们利用形变势模型对量子阱的能带进行了计算,很好地解释了实验结果。 【英文摘要】 Methods of photoluminescence(PL) photovoltage(PV), and timeresolved spectrum(TRS) are applied to study InGaAs/GaAs strained quantum well. We discover singlequantum well(SQW) and multiquantum well(MQW) have different spectral properties; and spectral intensity of MQW is much higher and spectral full width at half maximum (FWHM) is larger than those of SQW, but spectral FWHM of SQW increases more quickly than that of MQW, which is caused by excitonLO phonon coupling. The peaking energy of 11H obtained fro...福建省自然科学基金重点资助项目(A992001

Study on Schottky barrier of 4H-SiC at different anealing temperature

采用磁控溅射的方法在4H-SiC样品上分别沉积四种金属薄膜(Ag,Cu,Ni,Cr)形成Schottky 接触,研究了不同温度退火对Schottky势垒高度的影响。通过对样品的I-V测试结果的拟合,得到各金属/4H-SiC Schottky接触的势垒高度以及理想因子。在反向偏压100V下,样品的反向漏电流小于10-10A,说明样品的反向特性良好。样品经过不同温度的退火后,发现Cu、Ni与4H-SiC的势垒高度(SBH)随退火温度的升高而提高,超过某一温度,其整流特性变差; Ag、Cr的SBH在退火后降低。SBH与金属功函数呈线性关系(Cr金属除外),斜率为0.11。Schottky barriers were formed by sputtering the metals on the front side of 4H-SiC(Si face) by magnetron sputtering to study the rectifying characteristics of the contacts between the metals and 4H-SiC. The infections of the annealing under different temperature were also studied. Schottky barrier height (SBH) of metal/4H-SiC was evaluated from I-V measurements. Under a reverse voltage about 100 V, the reverse leaky current is below 0.1 nA. After annealed, the SBH of Cu/, Ni/4H-SiC was increased, but the SBH of Cr/, Ag/4H-SiC contact was decreased. The relationship between the work function of metals and the SBH was presented. The barrier height depends on the metal work function with slopes of 0.1 to 0.2 (except metal Cr).福建省厦门市科技项目(3502Z20031076

中国毒理学会会议论文集

目的:通过慢性应激模型和药理学手段研究NR2B亚基在抑郁症发病中的作用,选择性拮抗NR2B亚基的快速抗抑郁样作用及其神经生物学机制。方法:采用大鼠慢性应激抑郁模型,通过核团微注射方法研究内侧前额叶皮层内谷氨酸能NMDA受体不同亚基功能与抑郁样行为的关系。通过微透析技术及Western blot方法来检测内侧前额叶皮层内谷氨酸水平及相关分子的变化;通过多个抑郁模型及多种行为学测试(包括强迫游泳测试,&nbsp;</p

Aripiprazole versus other atypical antipsychotics for schizophrenia

BACKGROUND: In most western industrialised countries, second generation (atypical) antipsychotics are recommended as first line drug treatments for people with schizophrenia. In this review we specifically examine how the efficacy and tolerability of one such agent - aripiprazole - differs from that of other comparable second generation antipsychotics. OBJECTIVES: To evaluate the effects of aripiprazole compared with other atypical antipsychotics for people with schizophrenia and schizophrenia-like psychoses. SEARCH METHODS: We searched the Cochrane Schizophrenia Group Trials Register (November 2011), inspected references of all identified studies for further trials, and contacted relevant pharmaceutical companies, drug approval agencies and authors of trials for additional information. SELECTION CRITERIA: We included all randomised clinical trials (RCTs) comparing aripiprazole (oral) with oral and parenteral forms of amisulpride, clozapine, olanzapine, quetiapine, risperidone, sertindole, ziprasidone or zotepine for people with schizophrenia or schizophrenia-like psychoses. DATA COLLECTION AND ANALYSIS: We extracted data independently. For dichotomous data we calculated risk ratios (RR) and their 95% confidence intervals (CI) on an intention-to-treat basis based on a random-effects model. Where possible, we calculated illustrative comparative risks for primary outcomes. For continuous data, we calculated mean differences (MD), again based on a random-effects model. We assessed risk of bias for each included study. MAIN RESULTS: We included 12 trials involving 6389 patients. Aripiprazole was compared to olanzapine, risperidone and ziprasidone. All trials were sponsored by an interested drug manufacturer. The overall number of participants leaving studies early was 30% to 40%, limiting validity (no differences between groups).When compared with olanzapine no differences were apparent for global state (no clinically important change: n = 703, 1 RCT, RR short-term 1.00 95% CI 0.81 to 1.22; n = 317, 1 RCT, RR medium-term 1.08 95% CI 0.95 to 1.22) but mental state tended to favour olanzapine (n = 1360, 3 RCTs, MD total Positive and Negative Syndrome Scale (PANSS) 4.68 95% CI 2.21 to 7.16). There was no significant difference in extrapyramidal symptoms (n = 529, 2 RCTs, RR 0.99 95% CI 0.62 to 1.59) but fewer in the aripiprazole group had increased cholesterol levels (n = 223, 1 RCT, RR 0.32 95% CI 0.19 to 0.54) or weight gain of 7% or more of total body weight (n = 1095, 3 RCTs, RR 0.39 95% CI 0.28 to 0.54).When compared with risperidone, aripiprazole showed no advantage in terms of global state (n = 384, 2 RCTs, RR no important improvement 1.14 95% CI 0.81 to 1.60) or mental state (n = 372, 2 RCTs, MD total PANSS 1.50 95% CI -2.96 to 5.96).One study compared aripiprazole with ziprasidone (n = 247) and both the groups reported similar change in the global state (n = 247, 1 RCT, MD average change in Clinical Global Impression-Severity (CGI-S) score -0.03 95% CI -0.28 to 0.22) and mental state (n = 247, 1 RCT, MD change PANSS -3.00 95% CI -7.29 to 1.29).When compared with any one of several new generation antipsychotic drugs the aripiprazole group showed improvement in global state in energy (n = 523, 1 RCT, RR 0.69 95% CI 0.56 to 0.84), mood (n = 523, 1 RCT, RR 0.77 95% CI 0.65 to 0.92), negative symptoms (n = 523, 1 RCT, RR 0.82 95% CI 0.68 to 0.99), somnolence (n = 523, 1 RCT, RR 0.80 95% CI 0.69 to 0.93) and weight gain (n = 523, 1 RCT, RR 0.84 95% CI 0.76 to 0.94). Significantly more people given aripiprazole reported symptoms of nausea (n = 2881, 3 RCTs, RR 3.13 95% CI 2.12 to 4.61) but weight gain (7% or more of total body weight) was less common in people allocated aripiprazole (n = 330, 1 RCT, RR 0.35 95% CI 0.19 to 0.64). Aripiprazole may have value in aggression but data are limited. This will be the focus of another review. AUTHORS' CONCLUSIONS: Information on all comparisons are of limited quality, are incomplete and problematic to apply clinically. Aripiprazole is an antipsychotic drug with a variant but not absent adverse effect profile. Long-term data are sparse and there is considerable scope for another update of this review as new data emerges from the many Chinese studies as well as from ongoing larger, independent pragmatic trials