电极对CuPc/C60双层异质结有机太阳能电池光学性能的影响

采用传输矩阵法的光学模型以及MATLAB软件模拟了电极对CuPc/C₆₀双层异质结有机太阳能电池光学性能的影响。模拟结果表明:当把微腔结构引入到双层异质结电池时,对于入射电极,发现活性层的吸光率主要受其反射相移的影响而非其透射率,并且通过变化入射电极相移调节层到合适厚度可以使活性层吸光率相比于传统器件增加很多;而当把正负折射率交替的光子晶体引入到电池中作为背电极时,发现活性层的吸光率和背电极反射率、反射相移都有很大关系,在获得高反射率的同时可以通过调节背电极厚度从而使活性层在整个吸收光谱内的吸光率大于传统器件。     

基于酞菁钯和C60的异质结有机光敏场效应管

采用酞菁钯(PdPc)和C60两种有机半导体材料,通过真空热蒸镀法以不同的沉积顺序制备了两种不同结构的平面异质结有机光敏场效应管,并对这两种结构器件的光敏特性进行比较。在波长655 nm、光强100mW/cm2的光照条件下,结构为n+-Si/SiO2/PdPc/C60/Al(S&D)(PdPc/C60-OFET)器件的最大光暗比为2×103,光响应度为3 mA/W;而结构为n+-Si/SiO2/C60/PdPc/Al(S&D)(C60/PdPc-OFET)器件的最大光暗比为3×103,光响应度为11mA/W。实验结果表明C60/PdPc-OFET可以获得更好的光敏特性。     

深能级对AlGaInP/GaAs异质结双极晶体管性能的影响

用深能级瞬态光谱和光致发光(PL)方法研究了AlGaInP/GaAs异质结双极晶体管(HBT)发射区AlGaInP中的深能级.得到了两个深能级,分别为E_c-E_t1＝0.42eV和E_c-E_t2＝0.59eV,其复合截面为σ_n1＝6.27×10^-17cm²和σ_n2＝6.49×10^-20cm². 关键词：     

沟槽型发射极SiGe异质结双极晶体管新结构研究

提出了一种沟槽型发射极SiGe异质结双极晶体管新结构.详细分析了新结构中沟槽型发射极的引入对器件性能的影响,并对其机理进行研究.新型发射极结构通过改变发射极电流路径使电阻分区并联,在不增大结电容的前提下,有效减小发射极电阻,提高器件的频率特性.结果表明,新结构器件的截止频率和最大振荡频率分别增加至100.2 GHz和134.4 GHz,更重要的是沟槽型发射极结构的引入,在提高器件频率特性的同时,不会降低器件的电流增益,也不会增加结电容,很好实现了频率特性、电流增益和结电容之间的折中.对沟槽型发射极进行优化设计,改变侧墙高度和侧墙宽度.沟槽型发射极电阻不受侧墙高度改变的影响,频率性能不变;侧墙宽度增加,频率性能降低.     

Al2O3增强的Co2-C98/Al2O3/Si异质结的光伏效应

随着能源危机的加剧,太阳能电池作为开发和利用太阳能的一种普遍形式, 日益受到世界各国的重视.随着太阳能电池向着高效率、薄膜化、无毒性和原材料丰富的方向发展, 单纯的硅系太阳能电池已经无法达到这样的要求,因此新的材料和工艺的开发利用迫在眉睫. 本文研究了碳材料在硅异质节上实现光伏效应的改善及其可能在太阳能电池上的应用. 采用脉冲激光沉积方法制备的Co₂-C₉₈/Al₂O₃/Si异质结构在标准日光照射 (AM1.5, 100 mW/cm²)条件下,可获得0.447 V的开路电压和18.75 mA/cm²的电流密度, 转换效率可达3.27%.通过电容电压特性和暗条件下的电输运性能测量, 证明了氧化铝层的引入不但对单晶硅的表面起到了物理钝化作用,减小了反向漏电流, 使异质结界面缺陷、界面能级和复合中心减少,还起到了场效应钝化作用, 增加了异质结界面的势垒高度,增加了开路电压,使异质结的光伏效应显著增强.     

异质结界面电荷对突变InP/InGaAs异质结双极晶体管热场发射影响研究

异质结界面电荷的存在改变了异质结的内建势, 这引起了界面势垒尖峰高度和形状的扰动, 从而使异质结界面载流子的输运产生相应的变化, 最终导致异质结双极晶体管 (HBT) 性能的改变. 基于热场发射-扩散模型, 对异质结界面电荷对InP/InGaAs HBT性能的改变做了研究, 得到结论是正极性的界面电荷有利于InP/InGaAs HBT的直流和高频特性的改善, 而负极性的界面电荷则使器件的直流和高频特性变差. 关键词： InP/InGaAs异质结双极晶体管 界面电荷 内建势 热场发射     

沟槽型发射极SiGe异质结双极化晶体管新结构研究

提出了一种沟槽型发射极SiGe异质结双极化晶体管新结构. 详细分析了新结构中沟槽型发射极的引入对器件性能的影响,并对其机理进行研究. 新型发射极结构通过改变发射极电流路径使电阻分区并联,在不增大结电容的前提下,有效减小发射极电阻,提高器件的频率特性. 结果表明,新结构器件的截止频率和最大振荡频率分别增加至100.2 GHz和134.4 GHz,更重要的是沟槽型发射极结构的引入,在提高器件频率特性的同时,不会降低器件的电流增益,也不会增加结电容,很好实现了频率特性、电流增益和结电容之间的折中. 对沟槽型发射极进行优化设计,改变侧墙高度和侧墙宽度. 沟槽型发射极电阻不受侧墙高度改变的影响,频率性能不变;侧墙宽度增加,频率性能降低. 关键词： SiGe 异质结双极化晶体管 沟槽型发射极 发射极电阻     

基于波形测试的异质结双极型晶体管器件负载失配影响分析

大功率电磁脉冲冲击下,射频集成微系统内部容易产生负载失配问题,严重者可能导致系统失效甚至损毁。采用实时的波形测试方法,对射频器件的负载失配进而导致器件损毁的机理进行了分析。该方法以矢量网络分析仪作为主要测试仪器,结合回波信号注入和相位参考模块获得待测器件实时电压电流波形,进而分析其负载失配影响机制。采用有源负载牵引技术模拟大功率耦合电磁脉冲注入,进行了电压驻波比39∶1的失配测试,大幅提升了测试范围。创新性地采用了谐波信号源注入模拟杂散谐波电磁干扰,评估器件的谐波阻抗失配特性。通过实际异质结双极型晶体管（HBT）器件测试的结果表明,基波的失配会造成负载端电压过大,增加器件的易损性;基波和谐波频率的干扰分量组合使得输出电压瞬态峰值升高,造成器件的损毁。在进行电磁安全防护时,应同时考虑基波和谐波频率的防护。     

InP/In0.53Ga0.47As/InP双异质结双极型晶体管的仿真与分析

运用Silvaco-TCAD软件构建了InP/In_(0.53)Ga_(0.47)As/InP双异质结双极型晶体管模型,研究了掺杂浓度、厚度以及温度对器件特性的影响.结果表明:双异质结双极型晶体管DHBT的开启电压能达到约0.4V,当浓度达到4×10^(19) cm^(-3)的时候,电流增益可以达到一个最佳状态,其峰值能达到约125左右,且浓度对截止频率以及最高振荡频率没有太大的影响;当增大基区厚度时,电流增益会减小,改变厚度能够使DHBT输出特性得以提升,并且提高基区电流的注入;双异质结双极型晶体管具有很好的温度稳定性.     

衬底加热和电极修饰对提高有机场效应晶体管性能的影响

通过衬底加热和氧化钼(MoO3)修饰源漏极制备了并五苯有机场效应晶体管.研究了衬底温度和电极修饰层厚度对器件性能的影响.实验结果表明:当衬底温度为60℃、MoO3修饰层为10 nm时,器件性能获得了显著增强,场效应迁移率由原来的3.39×10-3 cm2/(V·s)提高到2.25 ×10-1 cm2/(V·s),阈值电压由12 V降低到3V.器件性能的改善归因于:衬底加热可以优化有源层形貌,改善载流子传输;而MoO3修饰层显著降低了电极与有源层之间的接触势垒,提高了载流子的注入.因此,衬底加热与电极修饰对于制备高性能有机场效应晶体管是不可或缺的优化手段.     

基于栅绝缘层表面修饰的有机场效应晶体管迁移率的研究进展

栅绝缘层的表面性质对有机场效应晶体管（OFETs）的半导体薄膜的形貌、晶粒生长的有序性和载流子的传输有着重大的影响．研究表明,通过改进栅绝缘层的表面性质,可以有效提高有机场效应晶体管的迁移率．本文综述了OFETs绝缘层表面的粗糙度和表面能对OFETs迁移率的影响,重点探讨了栅绝缘层表面修饰常用的方法,即自组装单层（SAMs）修饰和聚合物修饰与迁移率改进之间的研究进展．最后,展望了该研究方向未来可能的发展趋势．     

Channel length scaling and the impact of metal gate work function on the performance of double gate-metal oxide semiconductor field-effect transistors

In this paper, we study the effects of short channel on double gate MOSFETs. We evaluate the variation of the threshold voltage, the subthreshold slope, the leakage current and the drain-induced barrier lowering when channel length L _CH decreases. Furthermore, quantum effects on the performance of DG-MOSFETs are addressed and discussed. We also study the influence of metal gate work function on the performance of nanoscale MOSFETs. We use a self-consistent Poisson-Schrödinger solver in two dimensions over the entire device. A good agreement with numerical simulation results is obtained.     

Effects of concentration and annealing on the performance of regioregular poly（3-hexylthiophene） field-effect transistors

This paper investigates the effects of concentration on the crystalline structure, the morphology, and the charge carrier mobility of regioregular poly(3-hexylthiophene) (RR-P3HT) field-effect transistors (FETs). The RR-P3HT FETs with RR-P3HT as an active layer with different concentrations of RR-P3HT solution from 0.5~wt% to 2~wt% are prepared. The results indicate that the performance of RR-P3HT FETs improves drastically with the increase of RR-P3HT weight percentages in chloroform solution due to the formation of more microcrystalline lamellae and bigger nanoscale islands. It finds that the field-effect mobility of RR-P3HT FET with 2~wt% can reach 5.78× 10^-3~cm²/Vs which is higher by a factor of 13 than that with 0.5~wt%. Further, an appropriate thermal annealing is adopted to improve the performance of RR-P3HT FETs. The field-effect mobility of RR-P3HT FETs increases drastically to 0.09~cm²/Vs by thermal annealing at 150~℃, and the value of on/off current ratio can reach 10^4.     

High performance pentacene organic field-effect transistors consisting of biocompatible PMMA/silk fibroin bilayer dielectric

Pentacene organic field-effect transistors （OFETs） based on single- or double-layer biocompatible dielectrics of poly（methyl methacrylate） （PMMA） and/or silk fibroin （SF） are fabricated. Compared with those devices based on sin- gle PMMA or SF dielectric or SF/PMMA bilayer dielectric, the OFETs with biocompatible PMMA/SF bilayer dielectric exhibit optimal performance with a high field-effect mobility of 0.21 cm2/Vs and a current on/off ratio of 1.5 × 104. By investigating the surface morphology of the pentacene active layer through atom force microscopy and analyzing the elec- trical properties, the performance enhancement is mainly attributed to the crystallization improvement of the pentacene and the smaller interface trap density at the dielectric/organic interface. Meanwhile, a low contact resistance also indicates that a good electrode/organic contact is formed, thereby assisting the performance improvement of the OFET.     

Performance improvement in pentacene organic thin film transistors by inserting a C60 ultrathin layer

The contact effect on the performances of organic thin film transistors is studied here. A C₆₀ ultrathin layer is inserted between Al source--drain electrode and pentacene to reduce the contact resistance. By a 3 nm C₆₀ modification, the injection barrier is lowered and the contact resistance is reduced. Thus, the field-effect mobility increases from 0.12 to 0.52 cm²/(V·s). It means that inserting a C₆₀ ultra thin layer is a good method to improve the organic thin film transistor (OTFT) performance. The output curve is simulated by using a charge drift model. Considering the contact effect, the field effect mobility is improved to 1.15 cm²/(V·s). It indicates that further reducing the contact resistance of OTFTs should be carried out.     

利用不同阴极缓冲层来改善Pentacene/C60太阳能电池的性能

制备了结构为ITO/Pentacene/C₆₀/Al的双层光伏电池器件,在C₆₀/Al界面插入了常用的缓冲层材料bathocuproine(BCP)作为阴极缓冲层,通过优化BCP层的厚度来提高电池的性能并研究了阴极缓冲层的作用机理.实验发现,BCP厚度为10 nm时器件的效率最高,为0.46%.在此基础上,利用bathophenanthroline(Bphen)和3,4,9,10-Perylenetetracarb-oxylicdianhydride(PTCDA 关键词： 有机太阳能电池 Pentacene 60')" href="#">C₆₀ 缓冲层     

Properties of transistor based C60 thin film on polystyrene

This paper reports that the n-type organic thin-fihn transistors have been fabricated by using C60 as the active layer and polystyrene as the dielectric. The properties of insulator and the growth characteristic of C60 film were carefully investigated. By choosing different source/drain electrodes, a device with good performance can be obtained. The highest electron field effect mobility about 1.15 cm2/（V. s） could reach when Barium was introduced as electrodes. Moreover, the C60 transistor shows a negligible ＇hysteresis effect＇ contributed to the hydroxyl-free of insulator. The result suggests that polymer dielectrics are promising in applications among n-type organic transistors.     

Influence of the channel electric field distribution on the polarization Coulomb field scattering in In0.18Al0.82N/AIN/GaN heterostructure field-effect transistors

By making use of the quasi-two-dimensional （quasi-2D） model, the current-voltage （l-V） characteristics of In0AsA10.82N/A1N/GaN heterostructure field-effect transistors （HFETs） with different gate lengths are simulated based on the measured capacitance-voltage （C-V） characteristics and I-V characteristics. By analyzing the variation of the electron mobility for the two-dimensional electron gas （2DEG） with electric field, it is found that the different polarization charge distributions generated by the different channel electric field distributions can result in different polarization Coulomb field scatterings. The difference between the electron mobilities primarily caused by the polarization Coulomb field scatterings can reach up to 1522.9 cm2/V.s for the prepared In0.38AI0.82N/A1N/GaN HFETs. In addition, when the 2DEG sheet density is modulated by the drain-source bias, the electron mobility presents a peak with the variation of the 2DEG sheet density, the gate length is smaller, and the 2DEG sheet density corresponding to the peak point is higher.     

对以并五苯和酞菁铜为不同有源层的有机薄膜晶体管特性研究

通过扫描电镜和X射线衍射对SiO₂衬底上生长并五苯和酞菁铜薄膜的表面形貌进行表征,并得到在SiO₂衬底上生长的并五苯薄膜是以岛状结构生长,其大小约为100nm,且薄膜有较好的结晶取向,呈多晶态存在. 酞菁铜薄膜则没有表现出明显的生长机理,其呈非晶态存在. 还对通过掩膜的方法制作得以酞菁铜和并五苯为有源层的顶栅极有机薄膜晶体管的特性进行了研究. 有源层的厚度为40nm,绝缘层SiO₂的厚度为250nm,器件的沟道宽长比(W/关键词： 有机薄膜晶体管 并五苯薄膜 酞菁铜薄膜 μ_EF)')" href="#">场效应迁移率(μ_EF)