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1.
The electrical characteristics of CdTe-based Schottky-diode detectors of X-ray and γ radiation are studied. Experimental data are obtained for Al/p-CdTe diodes with a substrate resistivity from 102 to 109 Ωcm (300 K). The obtained results are interpreted in the context of the Sah-Noyce-Shockley theory of generation-recombination, taking into account the special features of the Schottky diode. It is shown that, when semi-insulating CdTe is used, the considerable forward currents observed are caused by electron injection into the substrate.  相似文献   

2.
Investigations of Al Schottky contacts to n-GaSb are presented. Barrier heights of 0.60±0.02 eV are found. Forward bias ideality factors between 2 at 300 K to 60 at 10 K, are explained by electron tunneling. Ideality factors yield donor concentrations significantly greater than nominal, accentuated by annealing, suggesting modification of the reactive GaSb surface  相似文献   

3.
Measurements have been made of the variation of the quantum efficiency of electroluminescence as a function of applied field in ZnS:Mn and ZnSe:Mn Schottky diodes. Under very high fields, the quantum efficiency unexpectedly reaches a maximum and then drops. An explanation is proposed which depends on the details of the band structures of ZnS and ZnSe.  相似文献   

4.
The conventional method used to determine the mechanism of current transport in a Schottky barrier diode can lead to erroneous inferences if a fluctuation of parameters, such as that which would occur in a large area diode, is present. This has been illustrated by taking a Gaussian variation of a parameter in case of diodes showing T0anomaly.  相似文献   

5.
The temperature-dependent electrical characteristics of the Au/n-Si Schottky diodes have been studied in the temperature range of 40-300 K. Current density-voltage (J-V) characteristics of these diodes have been analyzed on the basis of thermionic emission theory with Gaussian distribution model of barrier height. The basic diode parameters such as rectification ratio, ideality factor and barrier height were extracted. Under a reverse bias, the conduction process at low voltage is determined by Schottky emission over a potential barrier but at higher voltage the Poole Frenkel effect is observed. The capacitance-voltage (C-V) features of the Au/n-Si Schottky diodes were characterized in the high frequency of 1 MHz. The barrier heights values obtained from the J-V and C-V characteristics have been compared. It has been seen that the barrier height value obtained from the C-V measurements is higher than that obtained from the J-V measurements at various temperatures. Possible explanations for this discrepancy are presented. Deep level transient spectroscopy (DLTS) has been used to investigate deep levels in Au/n-Si. Three electron trap centers, having different emission rates and activation energies, have been observed. It is argued that the origin of these defects is of intrinsic nature. A correlation between C-V and DLTS measurements is investigated.  相似文献   

6.
固态倍频器是太赫兹源应用中的关键器件,如何利用非线性器件提高太赫兹倍频器件的效率是设计太赫兹固态电路的关键。本文介绍了利用肖特基二极管非线性特性设计固态太赫兹二倍频器的2种方法,即采用直接阻抗匹配和传输模式匹配设计了2种不同拓扑结构的170 GHz二倍频器,针对设计的结构模型,分别进行三维有限元电磁仿真和非线性谐波平衡仿真。仿真结果表明,在17 dBm输入功率的驱动下,倍频器在160 GHz~180 GHz输出频率范围内,倍频效率在15%左右,输出功率大于7 mW。最后对2种方法设计的倍频器结构进行了简单对比和分析,为今后太赫兹倍频研究和设计提供仿真方法。  相似文献   

7.
We report the successful use of the high-work-function, high-conductivity transparent conducting polymer PEDOT:PSS as the Schottky contact to form the Schottky junction (and thus Schottky diode) with the n-type semiconductor a-IGZO. The Schottky didoes exhibited a low apparent turn-on voltage, a high rectification ratio of >105 at ±1 V, and a decent ideality factor of ∼1.5–1.6. Detailed junction properties were systematically analyzed from J-V and C-V characteristics of the diodes. We also demonstrated the applications of PEDOT:PSS/a-IGZO Schottky junctions to various types of Schottky diodes, including the flexible, the transparent, and the flexible transparent PEDOT:PSS/a-IGZO Schottky diodes, by using different substrates and different counter electrodes.  相似文献   

8.
The current transport mechanisms in (Ni/Au)-AlN/GaN Schottky barrier diodes (SBDs) were investigated by the use of current-voltage characteristics in the temperature range of 80-380 K. In order to determine the true current transport mechanisms for (Ni/Au)-AlN/GaN SBDs, by taking the Js(tunnel), E0, and Rs as adjustable fit parameters, the experimental J-V data were fitted to the analytical expressions given for the current transport mechanisms in a wide range of applied biases and at different temperatures. Fitting results show the weak temperature dependent behavior in the saturation current and the temperature independent behavior of the tunneling parameters in this temperature range. Therefore, it has been concluded that the mechanism of charge transport in (Ni/Au)-AlN/GaN SBDs, along the dislocations intersecting the space charge region, is performed by tunneling.In addition, in order to analyze the trapping effects in (Ni/Au)-AlN/GaN SBDs, the capacitance-voltage (C-V) and conductance-voltage (G/ω-V) characteristics were measured in the frequency range 0.7-50 kHz. A detailed analysis of the frequency-dependent capacitance and conductance data was performed, assuming the models in which traps are located at the heterojunction interface. The density (Dt) and time constants (τt) of the trap states have been determined as a function of energy separation from the conduction-band edge (Ec  Et) as Dt≅(5-8)×1012, respectively.  相似文献   

9.
介绍了一个基于平面肖特基二极管的220 GHz倍频器。该倍频器工作在室温下,结构简单。为了实现倍频,将一个具有4个反向串联肖特基结的变容二极管安置在石英基片上,直流偏置通过一个石英微带构成的低通滤波器加到二极管上。所有的石英电路基片都用导电胶粘接在波导腔体上,波导腔体是E面剖分的,表面镀金。220 GHz倍频器的测试结果表明,在选择合适的偏置电阻时,该倍频器具有15 mW的输出功率和5%的效率。在213~230 GHz频段,二倍频器的输出功率均在10 mW以上,且带内的功率波动非常小。  相似文献   

10.
利用Matlab仿真模拟了石墨烯/P-CdTe肖特基结太阳能电池的光电特性。结果表明,电池的短路电流密度Jsc为23.9×10–3A/cm2、开路电压Voc为0.64 V、填充因子FF为79.0,转换效率η高达12%。与传统的氧化铟锡(ITO)电极比较,石墨烯柔韧性好,同时具备高透光和高导电的特性,可替代ITO作为新型电极材料来制备柔性薄膜太阳能电池。  相似文献   

11.
胡海帆  赵自然  马旭明  姜寿禄 《红外与激光工程》2019,48(7):722001-0722001(6)
基于Hammer-Head型滤波器结构,以及三维电磁软件所构建的肖特基二极管三维模型及电气模型,分别设计了250 GHz悬置微带线和普通微带线的二次谐波混频器。通过仿真设计与实物测试,对比分析两种结构混频器特性。测试结果表明,悬置微带线混频器在射频输入230~270 GHz范围内时,单边带变频损耗为8.6~12.7 dB,而普通微带线混频器在射频输入220~260 GHz范围内时,单边带变频损耗为8.4~11.4 dB。通过结果对比可见,悬置微带线混频器带宽较大,而普通微带线混频器的变频损耗更为平滑。此外,考虑微组装工艺中的不良因素,对仿真模型进行部分修正,计算结果与测试结果拟合较好。  相似文献   

12.
在分离式二极管的基础上,实现了220 GHz高效率的二倍频器结构。该倍频器的电路在450 μm宽,2.7 mm长的50 μm石英基片上实现。测试结果表明,在室温下当驱动功率在46.4~164 mW时,在214~226 GHz的频段内能够实现大于16%的倍频效率。另外,当驱动功率在161 mW时,倍频器在218 GHz频点能够输出最高功率32 mW,并且在多个频点拥有高于20%的倍频效率。实验证明,所实现的二倍频器能够作为660 GHz倍频链路的驱动前级使用。  相似文献   

13.
14.
为了缓解微波频段频谱资源的日益紧张,对太赫兹频段进行探索,介绍了一款基于GaAs肖特基二极管的330 GHz次谐波混频器。设计采用了整体综合设计的方法,进行高频结构模拟器(HFSS)与先进设计系统(ADS)联合仿真。优化过程中,电路不连续性通过HFSS仿真结果表征,电路传输特性和二极管非线性特性由ADS仿真结果表征,通过优化传输线参数,实现优化电路的目的。此方法增大了仿真优化空间,降低了设计难度。仿真结果显示,在300~350 GHz频段内,混频器的变频损耗小于8 dB。  相似文献   

15.
The low-frequency excess noise in Schottky barrier diodes has been investigated. In the ideal case where the saturation current is completely determined by thermionic emission of electrons, no 1/? noise will be produced in the barrier. The presence of trap states in the depletion region can lead to generation-recombination noise. At sufficient high forward currents 1/? noise can be generated in the series resistance of the Schottky diode. Deviations from the ideal diode, for example as a result of edge effects, produce 1/? noise and increase at the same time the ideality factor. It is empirically found that the 1/? noise level decreases very rapidly if the ideality factor tends to unity.  相似文献   

16.
The current transport and formations of potential barrier height in narrow Au/n-GaAs Schottky diodes (SD) with a contact surface in length of 200 μm, width of 1 and 4 μm have been investigated.It was determined that features of current transport are in good agreements with the thermionic emission theory in the forward bias as like high-quality conventional (flat) SD. Features of current transport in the reverse bias also is well described by thermionic emission theory, but it has specific features unlike IV characteristics flat SD.Forward bias of narrow SD current–voltage (IU) characteristics are represented by straight lines in semi-logarithmic scale in a wide range, nearly nine order of current up to 0.7 V with near unit ideality factor. In the beginning of the reverse voltage, the current practically was extremely low, by increasing in voltage the current jump in steps approximately for 3–4 order in voltage of 3–4 V, then current increases linear for 3–5 order in semi-logarithmic scale by increasing in voltage up to nearly 7 V.Numerical values of parameters such as the saturation currents, the operating barrier height, ideality factor, dimensionless factor are obtained. The correlations between ideality factor and dimensionless factor were meaningful.The energy diagrams of narrow SD have been drawn in absence and presence of forward and reverse voltage. It is found that electronic processes in narrow SD are well described by energy model of real narrow metal–semiconductor contacts. The additional electric field arising in near contact area of the semiconductor because of creating contact potential difference between contact surface and to it adjoining free surfaces of the metal and semiconductor.  相似文献   

17.
We describe developments to improve reliability and power handling for high frequency applications in whisker-contacted Schottky barrier diode mixers, detectors and multipliers fabricated using sputtered refractory metals and silicides. The lift-off process has been used to fabricate diodes on GaAs with ideality factors of 1.18 and 1.06 for W/GaAs and TiSix/GaAs contacts respectively.  相似文献   

18.
In this work, vertical Schottky barrier diodes (SBDs) were fabricated using a thin film of ZnO (50 nm) and PEDOT:PSS deposited by RF Sputtering and micro-drop casting, respectively. ITO and Au were used as ohmic contacts to ZnO and PEDOT:PSS films, respectively. The final structure consisted on Glass/ITO/ZnO/PEDOT:PSS/Au. The SBDs performance was characterized under dark and four different wavelengths conditions. From current–voltage characteristics, under dark and ambient conditions, a diode ideality factor of 1.4; a saturation current density of 1×10−9 A/cm2; a Schottky barrier height of 0.9 eV and a rectification ratio of 5 orders of magnitude at ±1 V were obtained. A carrier density of 5×1017 cm−3 for the ZnO film was estimated from capacitance–voltage measurements. For their characterization as photodiodes, the SBDs were illuminated with an ultra-bright UV (~380 nm) LED. A maximum UV responsivity of 0.013 A/W was obtained. The transient response of the SBDs was also analyzed with the UV LED connected to a pulsed signal of 0.5 Hz, demonstrating rise and fall times in the order of 200 ms. With a low temperature processing (<80 °C), visible-blind and UV photon-detection characteristics, the fabricated SBDs are candidates for flexible optoelectronics devices such as optical receivers for digital signal processing and measurement of light intensity.  相似文献   

19.
The dark current transport mechanism in electrochemically deposited n-CdS/p-CdTe thin film heterojunctions is investigated. The forward current measured in the temperature range between 200° and 305°K can be expressed as Jf = J0(T) exp (AV) and the reverse current can be expressed as Jr = ?CV exp ?CV[?λ(Vd?V)?(12)]. The current mechanisms are consistent with a multi step recombination-tunneling model.  相似文献   

20.
In order to select the optimal device for a particular application, designers must carefully analyze the tradeoffs between competing devices. Recent progress in SiC power rectifiers has resulted in the demonstration of high-voltage PiN and Schottky barrier diodes (SBDs). With both technologies maturing, power electronics engineers will soon face the task of selecting between these two devices. Until recently, the choice was simple, since silicon SBDs are only available for relatively low voltage applications. The choice is not as clear when considering SiC diodes, and guidelines for determining the proper application of each are needed. The purpose of this paper is to provide such guidelines, based on an analysis of the most significant tradeoffs involved.  相似文献   

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