表面修饰的ZnPc薄膜晶体管性能研究

以热生长的SiO2作为栅绝缘层,酞菁锌(ZnPc)作为有源层,研究了具有十八烷基三氯硅烷(OTS,C18H37SiCl3)/SiO2双绝缘层结构的有机薄膜晶体管(OTFT)。实验表明,采用OTS可以有效地降低SiO2栅绝缘层的表面能并改善表面的平整度,器件的场效应迁移率提高了3.5倍,漏电流从10-9A降到10-10A,阈值电压降低了5 V,开关电流比从103增加到104。结果显示,具有OTS/SiO2双绝缘层的器件结构能有效改进OTFT的性能。     

一种基于聚合物绝缘层的TIPS-pentacene晶体管性质研究

采用顶接触结构研究制备了以TIPS-pentacene为有源层、聚甲基丙烯酸甲酯(PMMA)为绝缘层的有机场效应晶体管(OFET),其中绝缘层采用溶液旋涂法制备,电极采用Au电极。通过原子力显微镜(AFM)和X射线衍射(XRD)技术对TIPS-pentacene在PMMA上的生长特性进行了详细分析,结果表明,器件获得了良好的电学特性,其场效应迁移率、阈值电压以及开关电流比分别为0.137 cm2/Vs、-19 V和9.74×104。对器件的稳定性也做了详细研究。     

纳米SiO2微球的尺寸调控、表面改性及应用

采用改进St?ber法,通过调节反应物的配比对纳米SiO2微球的尺寸进行调控;同时,为改善SiO2与有机体系的相容性,采用硅烷偶联剂γ-(甲基丙烯酰氧)丙基三甲氧基硅烷(KH570)对SiO2进行了表面改性.研究发现:乙醇和正硅酸乙酯的体积比显著影响SiO2的微球尺寸,乙醇用量越大,粒径越小;随着KH570用量的增加,SiO2表面羟基含量先急剧下降,后趋于稳定;含7％纳米SiO2的聚甲基丙烯酸酯(PMMA)复合凝胶电解质的电化学性能、导电性能和力学性能均明显增加.将纳米SiO2复合凝胶电解质组装为导电玻璃(ITO)‖SiO2/碳酸丙烯脂-高氯酸锂(PC-LiClO4)/PMMA‖金属-超分子聚合物‖ITO的透射式全固态电致变色器件,可在蓝紫色和黄绿色之间变色,与空白样品相比,其色差明显增大.     

原位聚合纳米SiO2／PMMA的制备与耐磨损性

考察了纳米SiO2／PMMA复合体系的耐磨损性．采用原位本体聚合方法制备．纳米SiO2／PMMA复合板,使用扫描电镜和光学显微镜对纳米SiO2及其复合物进行观察,采用砝码质量法测试复合物的耐磨损性．电镜观察结果表明：纳米SiO2较为均匀地分散在PMMA基体中,并被PMMA所包覆,包覆物的粒径介于30～100nm之间．耐磨损性测试结果表明：纳米SiO2的加入可提高PMMA复合物的耐磨损性和耐划痕性;当纳米SiO2用量为1．0％时,复合物的耐磨损性能提升39．7％．     

β-HEA对PMMA/SiO2纳米复合材料性能的影响

以丙烯酸-β-羟乙酯(β-HEA)为交联剂,采用溶胶-凝胶工艺制备了透明的PMMA/SiO2纳米复合材料,通过 IR、TMA、TGA和溶胶分数等研究了材料的结构和性能,结果表明复合材料中存在Si-O-C共价键,热稳定性明显优于有机玻璃,玻璃化转变温度为250 ℃以上,兼备有机玻璃和无机玻璃的性能优势.     

分散聚合法制备PMMA/SiO_2核壳型杂化微球

根据Stber法,用硅烷偶联剂对SiO2微球表面进行改性,制备了单分散改性SiO2微球,在此基础上采用分散聚合法制备出以SiO2为核、PMMA为壳层的核壳杂化微球。采用红外光谱、透射电镜和扫描电镜对2种微球进行了结构及形貌表征。     

水分子对有机场效应晶体管阈值电压稳定性的影响

以重掺杂Si片为衬底,SiO_2为栅绝缘层,并五苯为有源层,制备了有机场效应晶体管(OFETs),研究了空气中水汽对场效应性能的影响。实验表明:当器件较长时间放置在空气中时,吸附在并五苯和SiO_2接触面之间的水分子导致阈值电压漂移,器件的稳定性降低;经过热处理的器件的阈值电压漂移现象消失。提出了解释阈值电压漂移现象的模型,该模型可解释水分子在这个过程中所起的作用。     

酞菁材料光限幅器件的优化

以四叔丁基酞箐铟掺杂PMMA为基质材料,进行优化设计制备出光限幅器件,测试了该光限幅器件的光限幅性能,通过与单片未优化的酞菁铟的PMMA树脂片材性能的对比,可以看出在线性透过率相近的情况下,优化器件的光限幅性能有很大的提高.     

β-HEA对PMMA/SiO2纳米复合材料性能的影响

以丙烯酸-β-羟乙酯（β-HEA）为交联剂,采用溶胶-凝胶工艺制备了透明的PMMA/SiO2纳米复合材料,通过 IR、TMA、TGA和溶胶分数等研究了材料的结构和性能,结果表明复合材料中存在Si-O-C共价键,热稳定性明显优于有机玻璃,玻璃化转变温度为250 ℃以上,兼备有机玻璃和无机玻璃的性能优势.     

反向原子转移自由基法制备SiO2/PMMA复合粒子

采用反向原子转移自由基法,制备了SiO2/PMMA复合粒子.用硅烷偶联剂γ-甲基丙烯酰氧基丙基三甲氧基硅烷对纳米SiO2进行表面改性,通过亲水亲油性实验,确定了硅烷偶联剂的最佳用量(质量分数为10%).通过红外光谱和热重分析,证明聚甲基丙烯酸甲酯是通过化学键合接枝到纳米SiO2粒子表面.用透射电镜观察了纳米SiO2和复合粒子在乙醇中的分散情况,表明复合粒子的分散效果更好.     

氢离子敏场效应晶体管的研制及应用

氢离子敏场效应晶体管(HISFET)是一种新型的微型半导体敏感器件,其结构与金属—绝缘体—半导体场效应晶体管(MISFET)基本相同。HISFET用途广泛,具有许多比传统的玻璃电极优越的特性。本文论述了以Si_3N_4/SiO_2作为栅绝缘膜的HISFET的设计、制造和参数测试方法。初步讨论了其敏感机理。HISFET曾试用在医学上血液的PH值和工业废液的PH值的测试上。利用HISFET测得的数据同传统玻璃电极测得的数据是一致的。HISFET是一种很有发展前途的离子选择电极。     

PMMA／SiO2复合颗粒制备与表征

乳液聚合是对纳米颗粒改性的常用方法。但聚合效果不好且对改善纳米颗粒的分散作用不大。本实验引入硅烷自组装单分子层，采用无皂微乳液聚合法制备PMMA／SiO2复合颗粒。EDS、FTIR、TEM、LSS分析表明．纳米SiO2通过硅烷功能化，可以更有效地与MMA发生化学键合。复合颗粒在水中分散效果明显改善。不规则形状纳米SiO2通过组装而接近球形结构。复合颗粒具有很好的有机相容性和分散稳定性。     

Preparation and Properties of Paraffin/PMMA Shape-stabilized Phase Change Material for Building Thermal Energy Storage

The composite phase change material(PCM) consisting of phase change paraffin(PCP) and polymethyl methacrylate(PMMA) was prepared as a novel type of shape-stabilized PCM for building energy conservation through the method of bulk polymerization. The chemical structure, morphology, phase change temperature and enthalpy, and mechanical properties of the composite PCM were studied to evaluate the encapsulation effect of PMMA on PCP and determine the optimal composition proportion. FTIR and SEM results revealed that PCP was physically immobilized in the PMMA so that its leakage from the composite was prevented. Based on the thermo-physical and mechanical properties investigations, the optimal mass fraction of PCP in the composite was determined as 70%. The phase change temperature of the composite was close to that of PCP, and its latent heat was equivalent to the calculated value according to the mass fraction of PCP in the composite. For estimating the usability in practical engineering, thermal stability, reliability and temperature regulation performance of the composite were also researched by TG analysis, thermal cycling treatments and heating-cooling test. The results indicated that PCP/PMMA composite PCM behaved good thermal stability depending on the PMMA protection and its latent heat degraded little after 500 thermal cycling. Temperature regulation performance of the composite before and after thermal cycling was both noticeable due to its latent heat absorption and release in the temperature variation processes. The PCP/PMMA phase change plate was fabricated and applied as thermal insulator in miniature concrete box to estimate its temperature regulation effect under the simulated environmental condition. It can be concluded that this kind of PCP/PMMA shape-stabilized PCM with the advantages of no leakage, suitable phase change temperature and enthalpy, good thermal stability and reliability, and effective temperature regulation performance have much potential for thermal energy storage in building energy conservation.     

PMMA/SiO2杂化凝胶材料的研究

利用两步酸、碱催化溶胶－凝胶法及原位聚合法制备ＰＭＭＡ／ＳｉＯ２（聚甲基丙烯酸甲酯ＳｉＯ２）杂化凝胶,并对该材料进行红外分析,研究不同工艺条件下ＰＭ－ＭＡ／ＳｉＯ２杂化凝胶结构及性能。     

反向原子转移自由基法制备SiO_2/PMMA复合粒子

采用反向原子转移自由基法,制备了SiO2/PMMA复合粒子.用硅烷偶联剂γ-甲基丙烯酰氧基丙基三甲氧基硅烷对纳米SiO2进行表面改性,通过亲水亲油性实验,确定了硅烷偶联剂的最佳用量(质量分数为10%).通过红外光谱和热重分析,证明聚甲基丙烯酸甲酯是通过化学键合接枝到纳米SiO2粒子表面.用透射电镜观察了纳米SiO2和复合粒子在乙醇中的分散情况,表明复合粒子的分散效果更好.     

4H-SiC trench gate MOSFETs with field plate termination

Field plate(FP)-terminated 4H-SiC trench gate MOSFETs are demonstrated in this work.N+/P?/N?/N+multiple epitaxial layers were grown on 3-inch N+type 4H-SiC substrate by chemical vapor deposition(CVD),and then the 4H-SiC trench gate MOSFETs were fabricated based on the standard trench transistor fabrication.Current-voltage measurements in forward and reverse bias have been performed on different devices with and without FP protections.It is found that more than 60%of the devices protected with FP termination are able to block 850 V.The measurements also show that the devices have the small leakage currents 0.15 nA at 600 V and 2.5 nA at 800 V,respectively.The experimental results also were compared with the simulated results,which show good agreement with each other in the trend.The limited performance of the devices is mainly because of the damage induced on the trench sidewalls from the etching process and the quality of the SiO2 films.Therefore,the 4H-SiC trench gate MOSFETs are expected to be optimized by reducing the etching damage and growing high-quality SiO2 dielectric films.     

钾离子敏场效应晶体管及其光学特性

钾离子敏场效应晶体管(KISFET)是一种新型的半导体钾离子选择电极,可以用来测量溶液或体液中钾离子的活度。它的结构与普通金属—绝缘体—半导体场效应晶体管(MISFET)基本相同。它对钾离子起敏感作用的物质是涂敷在其栅区上的含有王冠化合物的PVC膜。本文论述了KISFET的设计、制造和测试方法。对KISFET的光学特性进行了实验。结果表明光照影响是由硅片表面产生的定态光电导引起的。KISFET是一种很有发展前途的化学半导体传感器件(CSSD)。