首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 78 毫秒
1.
High performance pentacene organic thin film transistors (OTFT) were designed and fabricated using SiO2 deposited by electron beam evaporation as gate dielectric material. Pentacene thin films were prepared on glass substrate with S--D electrode pattern made from ITO by means of thermal evaporation through self-organized process. The threshold voltage VTH was --2.75± 0.1V in 0---50V range, and that subthreshold slopes were 0.42± 0.05V/dec. The field-effect mobility (μEF) of OTFT device increased with the increase of VDS, but the μEF of OTFT device increased and then decreased with increased VGS when VDS was kept constant. When VDS was --50V, on/off current ratio was 0.48× 105 and subthreshold slope was 0.44V/dec. The μEF was 1.10cm2/(V.s), threshold voltage was --2.71V for the OTFT device.  相似文献   

2.
王颖  兰昊  曹菲  刘云涛  邵雷  张金平  李泽宏  张波  李肇基 《中国物理 B》2012,21(6):68504-068504
A novel high-voltage light punch-through(LPT) carrier stored trench bipolar transistor(CSTBT) with buried p-layer(BP) is proposed in this paper.Since the negative charges in the BP layer modulate the bulk electric field distribution,the electric field peaks both at the junction of the p base/n-type carrier stored(N-CS) layer and the corners of the trench gates are reduced,and new electric field peaks appear at the junction of the BP layer/N drift region.As a result,the overall electric field in the N drift region is enhanced and the proposed structure improves the breakdown voltage(BV) significantly compared with the LPT CSTBT.Furthermore,the proposed structure breaks the limitation of the doping concentration of the N-CS layer(NN CS) to the BV,and hence a higher NN CS can be used for the proposed LPT BP-CSTBT structure and a lower on-state voltage drop(Vce(sat)) can be obtained with almost constant BV.The results show that with a BP layer doping concentration of NBP = 7 × 1015 cm-3,a thickness of LBP = 2.5 μm,and a width of WBP = 5 μm,the BV of the proposed LPT BP-CSTBT increases from 1859 V to 1862 V,with NN CS increasing from 5 × 1015 cm-3 to 2.5 × 1016 cm-3.However,with the same N-drift region thickness of 150 μm and NN CS,the BV of the CSTBT decreases from 1598 V to 247 V.Meanwhile,the Vce(sat) of the proposed LPT BP-CSTBT structure decreases from 1.78 V to 1.45 V with NN CS increasing from 5 × 1015 cm-3 to 2.5 × 1016 cm-3.  相似文献   

3.
The electrical properties of devices made of doped 3-tetradecylpolypyrrole (PPy-C14) thin films sandwiched between indium-tin-oxyde (ITO) and gold metal electrodes are reported. The current density–voltage (JV) curves are asymmetric and nonlinear implying a non Ohmic rectifying contact. Using standard thermionic emission theory (Schottky) JV characteristics were satisfactorily fitted with a saturation current of J0=1.5×10-5 A cm-2, a barrier height of ϕb=0.7 eV, and an ideality factor of n=5.3. Characteristics from the plot of JV versus 1/T show that the activation energy of the thermionic emission process is higher below the glass transition temperature of PPy-C14 (Tg=45 °C) than above, which seems to indicate that the hopping conduction process is enhanced at T>Tg. The carrier concentration has been calculated from capacitance–voltage (C-V) measurements (N=1.9×1017 cm-3) allowing estimation of the carrier mobility μ=2.6×10-2 cm2 V-1 s-1. PACS 73.61.Ph; 73.40.Sx; 73.30.+y  相似文献   

4.
AlGaN/GaN high electron mobility transistors (HEMTs) are fabricated by employing SiN passivation, this paper investigates the degradation due to the high-electric-field stress. After the stress, a recoverable degradation has been found, consisting of the decrease of saturation drain current IDsat, maximal transconductance gm, and the positive shift of threshold voltage VTH at high drain-source voltage VDS. The high-electric-field stress degrades the electric characteristics of AlGaN/GaN HEMTs because the high field increases the electron trapping at the surface and in AlGaN barrier layer. The SiN passivation of AlGaN/GaN HEMTs decreases the surface trapping and 2DEG depletion a little during the high-electric-field stress. After the hot carrier stress with VDS=20 V and VGS=0 V applied to the device for 104 sec, the SiN passivation decreases the stress-induced degradation of IDsat from 36% to 30%. Both on-state and pulse-state stresses produce comparative decrease of IDsat, which shows that although the passivation is effective in suppressing electron trapping in surface states, it does not protect the device from high-electric-field degradation in nature. So passivation in conjunction with other technological solutions like cap layer, prepassivation surface treatments, or field-plate gate to weaken high-electric-field degradation should be adopted.  相似文献   

5.
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 μEF)')" href="#">场效应迁移率(μEF)  相似文献   

6.
制作了底栅极顶接触有机薄膜晶体管器件,60 nm的pentacene被用作有源层,120 nm热生长的SiO2作为栅极绝缘层.通过采用不同自组装修饰材料对器件的有源层与栅极绝缘层之间的界面进行修饰,如octadecyltrichlorosilane (OTS),phenyltrimethoxysilane (PhTMS),来比较界面修饰层对器件性能的影响.同时对带有PhTMS修饰层的OTFTs器件低栅极电压调制下的场效应行为及其载流子的传输机理进行研究.结果得到,当|V 关键词: 有机薄膜晶体管 自组装单分子层 场效应迁移率 低栅极调制电压  相似文献   

7.
Thep-Si/HF-electrolyte interface was characterized by capacitance–voltage (C–V) and current–voltage (I–V) studies. At low frequency, the measured capacitance exhibits two maxima: one in the weak accumulation regime (around 0.8 V [SCE]) and the other in the strong accumulation regime (around 2.6 V [SCE]), both of which disappear at high frequency. The disappearance of the two capacitance maxima is attributed to the slow response of interface traps to high frequencies. The flat-band potential, VFB, is found to be frequency dependent. The surface state densities corresponding to the two capacitance maxima are estimated to be 3.2×1011 cm-2 and 2.4×1011 cm-2, respectively. The in situ I–V characteristics distinguish pore formation, transition and electropolishing regions. Porous Si synthesized at 50 mA cm-2 gives a broad photoluminescence peak around 2.04 eV at 300 K. Received: 4 September 2000 / Accepted: 9 February 2001 / Published online: 26 April 2001  相似文献   

8.
Zn–Sn–O (ZTO) thin film transistors (TFTs) were fabricated with a Cu source/drain electrode. Although a reasonably high mobility (μFE) of 13.2 cm2/Vs was obtained for the ZTO TFTs, the subthreshold gate swing (SS) and threshold voltage (Vth) of 1.1 V/decade and 9.1 V, respectively, were inferior. However, ZTO TFTs with Ta film inserted as a diffusion barrier, exhibited improved SS and Vth values of 0.48 V/decade and 3.0 V, respectively as well as a high μFE value of 18.7 cm2/Vs. The improvement in the Ta‐inserted device was attributed to the suppression of Cu lateral diffusion into the ZTO channel region. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)  相似文献   

9.
张倩  张玉明  元磊  张义门  汤晓燕  宋庆文 《中国物理 B》2012,21(8):88502-088502
In this paper we report on a novel structure of a 4H-SiC bipolar junction transistor with a double base epilayer that is continuously grown.The measured dc common-emitter current gain is 16.8 at IC = 28.6 mA(J C = 183.4 A/cm2),and it increases with the collector current density increasing.The specific on-state resistance(Rsp-on) is32.3mΩ·cm 2 and the open-base breakdown voltage reaches 410 V.The emitter N-type specific contact resistance and N + emitter layer sheet resistance are 1.7×10-3 Ω·cm2 and 150 /,respectively.  相似文献   

10.
An In0.53Ga0.47As/InP heterojunction-channel tunneling field-effect transistor (TFET) with enhanced subthreshold swing (S) and on/off current ratio (Ion/Ioff) is studied. The proposed TFET achieves remarkable characteristics including S of 16.5 mV/dec, on-state current (Ion) of 421 μA/μm, Ion/Ioff of 1.2 × 1012 by design optimization in doping type of In0.53Ga0.47As channel at low gate (VGS) and drain voltages (VDS) of 0.5 V. Comparable performances are maintained at VDS below 0.5 V. Moreover, an extremely fast switching below 100 fs is accomplished by the device. It is confirmed that the proposed TFET has strong potentials for the ultra-low operating power and high-speed electron device.  相似文献   

11.
Implantation of any ions at a sufficiently high dose and energy (E) into single-crystalline Si leads to the creation of amorphous Si (aSi), with damages peaking near the projected range (R p) of implanted species. Enhanced hydrostatic pressure (HP) at a high temperature (HT) influences the recrystallization of aSi. The structure of self-implanted Czochralski silicon (Si+ dose, D=2×1016 cm?2, E=150 keV, R p=0.22 μm) processed for 5 h at 1400 or 1520 K under HPs up to 1.45 GPa was investigated by X-ray, secondary ion mass spectrometry and photoluminescence methods. The implantation of Si produces vacancies (V) and self-interstitials (Sii). Vacancies and Siis form complex defects at HT–HP, also with contaminants (e.g. oxygen, always present in Czochralski silicon). The mobility and recombination of V and Sii as well as the kinetics of recrystallization are affected by HP, thus processing at HT–HP affects the recovery of aSi.  相似文献   

12.
Antimony trisulphide (Sb2S3) films were prepared by thermal evaporation technique on n-type single crystal Si substrates to fabricate p-Sb2S3/n-Si heterojunctions. The electrical transport properties of the p–Sb2S3/n-Si heterojunctions were investigated by current–voltage (IV) and capacitance–voltage (CV) measurements. The temperature-dependent IV characteristics revealed that the forward conduction was determined by multi-step tunnelling current and the activation energy of saturation current was about 0.54 eV. The 1/C2V plots indicated the junction was abrupt and the junction built-in potential was 0.6 V at room temperature and decreased with increasing temperature. The solar cell parameters have been calculated for the fabricated cell as Voc = 0.50 V, Jsc = 14.53 mA cm−2, FF = 0.32 and η = 4.65% under an illumination of 50 mW cm−2.  相似文献   

13.
Single crystals of nickel-doped sodium potassium sulphate were grown by slow evaporation method at room temperature. From the nature and position of the bands observed, a successful interpretation of all the observed bands could be made assuming the octahedral symmetry for the Ni2 + ion in the crystal. The bands have been ascribed to transitions from the ground3A2g(F) state to the excited3T2g(F),1Eg(D),3T1g(F),1T2g(D) and3T1g(P) states. The experimental and calculated energies are in good agreement. The crystal field parameters derived areDq= =880 cm–1,B= 900cm–1 andC=3600 cm–1.One of the authors, Sujatha John expresses her thanks to the Secretary and the Principal, R. B. V. R. Reddy College, Hyderabad for according her permission to pursue the M. Phil. course.  相似文献   

14.
Defective graphene nanosheets (dGN4V) with 5-9, 5-8-5, and point defects were synthesised by a sonoelectrochemical method, where a potential of 4 V (vs. Ag/AgCl) was applied to drive the rapid intercalation of phosphate ions between the layers of the graphite foil as a working electrode. In addition to these vacancies, double vacancy defects were also created when the applied potential was increased to 8 V (dGN8V). The defect density of dGN8V (2406 μm−2) was higher than that of dGN4V (1786 μm−2). Additionally, dGN8V and dGN4V were applied as catalysts for the hydrogen peroxide reduction reaction (HPRR). The mass activity of dGN8V (1.31 × 10−2 mA·μg−1) was greater than that of dGN4V (1.17 × 10−2 mA·μg−1) because of its high electrochemical surface area (ECSA, 1250.89 m2·g−1) and defect density (ND, 2406 μm−2), leading to low charge transfer resistance on the electrocatalytic interface. The ECSA and ND of dGN4V were 502.7 m2·g−1 and 1786 μm−2, respectively. Apart from its remarkable HPRR activity, the cost-effective dGN8V catalyst also showed potential as an amperometric sensor for the determination of H2O2.  相似文献   

15.
GaAs MIS field effect transistors with a Ge3N4 dielectric gate have been investigated. No hysteresis loop and drain current drift has been observed in theI D -V Dcharacteristics. However, performance of the devices have been found to be limited by the contact resistance. FromI DS 1/2 -V G plot, the threshold voltage and effective channel mobility of the transistor have been obtained as -4.5V and 2800cm2v–1s–1, respectively. A maximum dc transconductance of 68 mS/mm of gate width has been achieved.  相似文献   

16.
The drift velocity v+ of positrons in Si has been measured by observing the Doppler shift of the annihilation γ's. The electric field dependence of v+ yields the positron mobility μ+: at 80 K μ+=460±20 cm2V-1 sec-1 and at 184 K μ+=173±15 cm2V-1 sec-1.  相似文献   

17.
吴丽娟  胡盛东  张波  罗小蓉  李肇基 《中国物理 B》2011,20(8):87101-087101
This paper proposes a new n +-charge island (NCI) P-channel lateral double diffused metal-oxide semiconductor (LDMOS) based on silicon epitaxial separation by implantation oxygen (E-SIMOX) substrate.Higher concentration self-adapted holes resulting from a vertical electric field are located in the spacing of two neighbouring n +-regions on the interface of a buried oxide layer,and therefore the electric field of a dielectric buried layer (E I) is enhanced by these holes effectively,leading to an improved breakdown voltage (BV).The V B and E I of the NCI P-channel LDMOS increase to-188 V and 502.3 V/μm from 75 V and 82.2 V/μm of the conventional P-channel LDMOS with the same thicknesses SOI layer and the buried oxide layer,respectively.The influences of structure parameters on the proposed device characteristics are investigated by simulation.Moreover,compared with the conventional device,the proposed device exhibits low special on-resistance.  相似文献   

18.
许政一  凌亚文  杨华光 《物理学报》1990,39(11):1785-1790
利用低频交变电场在某些离子导体中能引起偏振态改变的光衍射特性,发展了一种测量这些离子导体的导电基本参数的新方法,并且用它测定了α-LiIO3单晶的基本离子导电参数,测得其载流子的迁移率激活能Eμ=0.36eV;夫仑克耳缺陷的形成能为EM=0.59eV;300K时正、负载流子的数密度均为1.6×1017cm-3,相对浓度均为1.07×10-5;当所加电场反平行于晶体的自发极化强 关键词:  相似文献   

19.
20.
轩瑞杰  刘慧宣 《中国物理 B》2012,21(8):88104-088104
A battery drivable low-voltage transparent lightly antimony(Sb)-doped SnO2 nanowire electric-double-layer (EDL) field-effect transistor (FET) is fabricated on an ITO glass substrate at room temperature. An ultralow operation voltage of 1 V is obtained on account of an untralarge specific gate capacitance (- 2.14 μF/cm2) directly bound up with mobile ions-induced EDL (sandwiched between the top and bottom electrodes) effect. The transparent FET shows excellent electric characteristics with a field-effect mobility of 54.43 cm2/V. s, current on/off ration of 2 × 104, and subthreshold gate voltage swing (S = dVgs/d(logIds)) of 140 mV/decade. The threshold voltage Yth (0.1 V) is estimated which indicates that the SnO2 namowire transistor operates in an n-type enhanced mode. Such a low-voltage transparent nanowire transistor gated by a microporous SiO2-based solid electrolyte is very promising for battery-powered portable nanoscale sensors.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号