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The current-voltage (I-V-T) characteristics of an inhomogeneous n-type GaAs Schottky barrier diode have been investigated by numerical analysis using the modified thermionic emission (TE) current equation by Tung in the 40–320 K range at 40 K intervals. This total current (TC) equation consists of TE current and the patch current components. The patch current dominates through the low Schottky barrier height patches at low temperatures. From the I-V-T characteristics given for three different standard deviations (σ) at each substrate doping value N d , we have determined the temperatures at which the patch current begins to dominate. The starting temperature of the patch current has decreased as the σ and N d values decrease. It has been seen that the temperature at which the patch current component begins to dominate is about 120, 80, and 60 K for σ 4 , σ 3 , and σ 2 at N d = 1.0 × 10 14 c m − 3 or N d = 1.0 × 10 15 c m − 3 , respectively; 160, 120, and 80 K at N d = 5.0 × 10 15 c m − 3 ; and 200, 160, and 80 K at N d = 1.0 × 10 16 c m − 3 , respectively. Moreover, for the substrate with high doping, it has been observed that the I-V curve of the patch current component or the TC shifts toward higher voltages than the expected position at low temperatures. Thus, from the I-V-T characteristics, it has appeared that Tung's pinch-off model tends to be more applicable to lightly doped semiconductors. Moreover, the TC equation should be used at high temperatures because the I-V curves at high temperatures belong to the TE component, and the patch current expression without the TE component should be especially used for fit to the experimental curves at low temperatures. [ABSTRACT FROM AUTHOR]

We have investigated the behavior of current flow across an inhomogeneous Schottky diode (SD) as a function of temperature by numerical simulation. We have used the modified thermionic emission (TE) current expression with a Gaussian distribution of potential barrier heights. This modified TE model assumes the presence of a series of low-barrier patches at the Schottky contact and semiconductor interface. First, we have discussed the behavior of the patch current compound relative to the TE compound in the inhomogeneous SD at 300, 200, and 100 K, as a function of standard deviation and the number of circular patches N. Then, we have investigated the behavior of temperature- and bias-dependent and bias-independent current vs voltage (I – V – T) characteristics in the 75–300 K range. In bias-dependent I – V – T curves obtained for σ 1 = 4.35 × 10 − 5 c m 2 / 3 V 1 / 3 and σ 2 = 7.35 × 10 − 5 c m 2 / 3 V 1 / 3 at N 1 = 1.81 × 10 6 or N 2 = 1.81 × 10 8 , an intersection behavior has been observed in the I – V curve at 75 K for σ 2 at both N values; however, the same behavior has been not observed for σ 1 at both N values due to σ 1 < σ 2. That is, the current for σ 2 at 75 K has exceeded the current at higher temperatures. This behavior has been ascribed to the effective BH to decrease with decreasing temperature value. In the I – V – T curves independent of bias, such an intersection has not been observed for σ 1 while it has been observed for σ 2 in the I – V curves at both 75 and 100 K. Thus, it has been concluded that the bias-depende σ nt I – V equations must be used to avoid this intersection behavior while fitting the experimental I – V curve of an SD to the theoretical I – V curve. [ABSTRACT FROM AUTHOR]

Many of the device parameters measured in scientific research and engineering applications depend on the ambient temperature to varying degrees. A Schottky barrier diode (SBD) is in direct contact with the environment, namely, gas, pressure, and temperature; therefore, a change in the state of the Schottky contact (SC) immediately affects its parameters in contrast to the p-n junction and semiconductor transistors. The temperature sensitivity capability of the Au/n-GaAs SBDs has been analyzed by numerical simulation of its current–voltage characteristics using a thermionic emission relation. The obtained results from the simulation study have shown that the thermal sensitivity of the SBDs has increased with a decrease in the current level value at the same SC area size, and it has decreased with a decrease in the SC area size under the same current level. Moreover, it has been concluded from the fact that a SBD with a large SC area should be operated for the cryogenic temperature range under a low current level rather than high current levels. The results of this kind of study can help us to select the SC dimension suitable for many purposes in scientific research and engineering applications. [ABSTRACT FROM AUTHOR]

Among the multiferroics, yttrium manganite YMnO3 (YMO) is one of the most frequently studied magnetic ferroelectric oxides and has attracted a great deal of concern, thanks to its potential magnetoelectric features. Furthermore, it has been reported in the literature that yttrium manganite is a useful interface material in thin film devices. It has been documented that the dopant into Y and/or Mn site(s) plays significant roles on the electrical and magnetic properties of YMO. The YMn0.95Os0.05O3 (YMOO) oxide powders were prepared by the well-known solid-state reaction technique. The YMOO thin films were deposited on the p-Si (100) substrate via a radio frequency sputtering method with a thickness of approximately 62 nm. The oxidation states of the constituted elements have been investigated by using the X-ray photoelectron spectroscopy method. Furthermore, the surface features of the obtained thin film have been investigated using a scanning electron microscope measurement. The I–V measurements were performed in the 50–310 K range, and consequently, the Schottky diodelike reverse and forward bias I–V characteristics were observed in the Al/YMOO/p-Si heterojunction. Moreover, the ideality factor and the barrier height values were calculated as 0.77 and 2.23 at room temperature, respectively. [ABSTRACT FROM AUTHOR]

We have discussed the thermal sensing capability under a constant current level and current versus voltage (I–V) traces by measuring the temperature of high series resistance Pt/n-GaP/Al/Ti Schottky structures in the 100−320 K range. The Rs values of 35 Ω and 4.50 × 103 kΩ for the device have been determined from I–V traces at 320 and 100 K, respectively. The thermal sensing (V–T) curves are expected to give a straight line at each current level. However, the V–T curves have deviated upward from linearity due to the high Rs value of the device after a certain temperature. The deviation point from linearity in V–T traces shifts to higher temperatures with an increase in bias voltage and current level. Thereby, the straight-line interval portion of the V–T curve has become too small with an increase in the current value. The thermal sensing coefficient α changed from 2.49 mV/K at 10 μA to 3.21 mV/K at 0.50 nA. Therefore, it has been concluded that the Pt/n-GaP/Al/Ti Schottky barrier (SB) is preferable for thermal sensor applications at the small current levels of 0.50, 1.0, 2.0, and 10.0 nA with high sensitivity up to a minimum temperature of 100 K. From I–V curves, q Φ b 0 and ideality factor values have ranged from 1.200 eV and 1.066 at 320 K to 0.854 eV and 1.705 at 100 K. It has been reported in the literature that the large SB height leads to a better temperature response. [ABSTRACT FROM AUTHOR]

We have investigated the thermal sensitivity of Pt/epitaxy n-Si/n+Si Schottky barrier (SB) diodes as a function of the Schottky contact (SC) area. Moreover, we have reported the current-voltage (I-V) of these SB diodes in the temperature range of 40–320 K. The V-T characteristics for the thermal sensitivity have been measured in the 20–320 K range with steps of 2 K at different current levels, which range from 10 nA to 100 μA. The V-T curves have given two linear regions at each current level, one in the low temperature (LT) region and the other in the high temperature (HT) region. The thermal sensitivity coefficient α has increased with the decreasing current level for all diodes. The α value has increased with increasing SC area at the same current level in the LT region. The case may be attributed to the barrier inhomogeneity at low temperatures. However, in the HT region, the α value has decreased very slightly with increasing SC area at the same current level, which may be ascribed to the fact that the current transport occurs over a lateral homogeneous SB height at high temperatures. The SB height and ideality factor n values from the I-V-T curves have remained approximately unchanged from 170 to 320 K. [ABSTRACT FROM AUTHOR]

In this study, Ti/n-GaAs Schottky barrier diode has been fabricated by DC magnetron sputtering. The current-voltage, capacitance-voltage, and conductance-voltage characteristics of Ti/n-GaAs diode have been investigated in the temperature range of 80-320 K. The ideality factor and barrier height values have been calculated from the forward current-voltage characteristics. The variation of the diode parameters with the sample temperature has been attributed to the presence of the lateral inhomogeneities of the barrier height. The temperature dependent capacitance-voltage characteristics have been measured to calculate the carrier concentration, diffusion potential, barrier height, and temperature coefficient of the barrier height (α=-0.65 meV K-1). The fact that the temperature coefficient of the barrier height changes from metal to metal has been ascribed to the chemical nature of the contact metal or metal electronegativity. [ABSTRACT FROM AUTHOR]

We report the current-voltage (I-V) and capacitance-voltage characteristics (C-V) of Ni/n-GaN Schottky diodes. Gallium nitride is a highly promising wide band gap semiconductor for applications in high power electronic and optoelectronic devices which require Schottky barriers for modulating the channel mobile charge. The I-V and C-V characteristics of the diodes have been measured in the temperature range of 80-400 K with steps of 20 K. Thermal carrier concentration and barrier height versus temperature plots have been obtained from the C-2-V characteristics, and a value of α=-1.40 meV/K for temperature coefficient of the barrier height. The modified activation energy plot according to the barrier inhomogeneity model has given the Richardson constant A* as 80 or 85 A/(cm2 K2). [ABSTRACT FROM AUTHOR]

To obtain detailed information about the conduction process of the Ag/p-GaN Schottky diodes (SDs) fabricated by us, we measured the I-V characteristics over the temperature range of 80–360 K by the steps of 20 K. The slope of the linear portion of the forward bias I-V plot and nkT=E0 of the device remained almost unchanged as independent of temperature with an average of 25.71±0.90 V-1 and 41.44±1.38 meV, respectively. Therefore, it can be said that the experimental I-V data quite well obey the field emission model rather than the thermionic emission or thermionic field emission model. The study is a very good experimental example for the FE model. Furthermore, the reverse bias saturation current ranges from 8.34×10-8 A at 80 K to 2.10×10-7 A at 360 K, indicating that the charge transport mechanism in the Ag/p-GaN SD is tunneling due to the weak temperature dependence of the saturation current. The possible origin of high experimental characteristic tunneling energy of E00=39 meV, which is ten times larger than possible theoretical value of 3.89 meV, is attributed to the accumulation of a large amount of defect states near the GaN surface or to the deep level defect band induced by high doping or to any mechanism which enhances the electric field and the state density at the semiconductor surface. [ABSTRACT FROM AUTHOR]

Presents a study that prepared a metal-semiconductor-metal Schottky diode, in which gold and aluminum were used as metals and freshly prepared polythiophene as a semiconductor. Role played by metal-semiconductor devices in contemporary electronics; Attempts at fabrication and interpretation of current-voltage and capacitance-voltage characteristics of metal-polymer Schottky diodes. Measurement of I-V characteristics of the diode using a Keithly model 610 C electrometer.