Electrical Characteristics of n-Type Nanocrystalline FeSi2/Intrinsic Si/p-Type Si Heterojunctions Prepared by Facing-Targets Direct-Current Sputtering

2013 ◽  
Vol 446-447 ◽  
pp. 88-92
Author(s):  
Nathaporn Promros ◽  
Suguru Funasaki ◽  
Ryūhei Iwasaki ◽  
Tsuyoshi Yoshitake

n-Type nanocrystalline FeSi2/intrinsic Si/p-type Si heterojunctions were prepared by FTDCS. In order to estimate their diode parameters such as ideality factor, barrier height and series resistance, their current-voltage characteristics were measured in the temperature range from 300 to 77 K and analyzed on the basis of thermionic emission theory and Cheungs method. Based on thermionic emission theory, the ideality factor was calculated from the slope of the linear part from the forward lnJ-V characteristics. The barrier height was calculated once the saturation current density was derived from the straight line intercept of lnJ-V plot at a zero voltage. The obtained results exhibit an increase of ideality factor and a decrease of barrier height at low temperatures, which might be owing to inhomogeneity of material and non-uniformity of charge at the interface. Based on Cheungs method, the ideality factor and barrier height were estimated from y-axis intercept of dV/d (lnJ)J plot and y-axis intercept of H(J)J plot, respectively. The series resistance was analyzed from the slopes of dV/d (lnJ)J and H(J)J plots. The values of ideality factor and barrier height obtained from this method are in agreement with those obtained from the thermionic emission theory. The obtained series resistances from dV/d (lnJ)J and H(J)J plots, which were approximately equal to each others, were increased as the temperature decreased. This result should be owing to the increased ideality factor and remarkably reduced carrier concentrations at low temperatures.

2014 ◽  
Vol 1043 ◽  
pp. 57-61
Author(s):  
Nathaporn Promros ◽  
Suguru Funasaki ◽  
Motoki Takahara ◽  
Mahmoud Shaban ◽  
Tsuyoshi Yoshitake

n-Type β-FeSi2/p-type Si heterojunctions have been successfully fabricated by facing-targets direct-current sputtering at a substrate temperature of 600 °C without post-annealing and their current-voltage characteristics were measured at low temperatures ragne from 300 K down to 50 K. The ideality factor, saturation current and series resistance were estimated by the thermionic emission theory and Cheung’s method. By the thermionic emission theory, we calculated the ideality factor from the slope of the linear part from the forward lnJ-V and estimated the saturation current density from the straight line intercept of lnJ-V at a zero voltage. As decreasing temperatures from 300 down to 50 K, the value of ideality factor increased from 1.2 to 15.6, while the value of saturation current density decreased from 1.6 × 10−6 A/cm2 to 3.8 × 10−10 A/cm2. From the plots of dV/d (lnJ)-J and H(J)-J by Cheung’s method, the obtained values of series resistances are consistent with each other. The series resistances analyzed from both plots increased as decreasing temperatures.


2015 ◽  
Vol 1103 ◽  
pp. 91-96
Author(s):  
Nathaporn Promros ◽  
Suguru Funasaki ◽  
Motoki Takahara ◽  
Ryūhei Iwasaki ◽  
Mahmoud Shaban ◽  
...  

Mesa structural n-type nanocrystalline-FeSi2/p-type Si heterojunctions were successfully fabricated by a lift-off technique combined with a photolithography process. Their current-voltage characteristics were measured at low temperatures range from 300 K down to 60 K. We estimated their diode parameters such as ideality factor, barrier height and series resistance based on the thermionic emission theory and Cheung’s method. From the estimation by the thermionic emission theory, the obtained results show an increase of ideality factor and a decrease of barrier height at low temperatures. The estimation by Cheung’s method shows that the values of ideality factor and barrier height are in agreement with those obtained from the thermionic emission theory. The obtained series resistances from dV/d (lnJ)-J and H(J)-J plots, which are approximately equal to each others, are increased at low temperatures.


2015 ◽  
Vol 1120-1121 ◽  
pp. 435-439
Author(s):  
Nathaporn Promros ◽  
Dalin Prajakkan ◽  
Nantharat Hongsa ◽  
Nattanee Suthayanan ◽  
Phongsaphak Sittimart ◽  
...  

In this work, n-type β-FeSi2/intrinsic Si/p-type Si heterojunctions were prepared by facing-targets direct-current sputtering. We measured their current-voltage characteristics at low temperatures ranging from 300 K down to 50 K and investigated their ideality factor, saturation current and series resistance using thermionic emission theory and Cheung’s method. From thermionic emission theory, the ideality factor and saturation current density were calculated from the slope of the linear part from the forward lnJ-V and the straight line intercept of lnJ-V at zero voltage, respectively. When the temperature decreased from 300 K down to 50 K, the ideality factor increased from 1.12 to 11.13, whereas the saturation current density decreased from 2.09 × 10-6 A/cm2 to 1.06 × 10-9 A/cm2. Using Cheung’s method, we plotted the relations of dV/d(lnJ)-J and H(J)-J in order to estimate the series resistance from the slope of both plots. In addition, we estimated the ideality factor from a y-axis intercept of the dV/d(lnJ)-J plot. The series resistances from both plots were consistent with each other and increased with the decreasing temperature. The ideality factor estimated by Cheung’s method was in agreement with that obtained from estimation by thermionic emission theory.


2015 ◽  
Vol 1119 ◽  
pp. 189-193
Author(s):  
Nathaporn Promros ◽  
Motoki Takahara ◽  
Ryuji Baba ◽  
Tarek M. Mostafa ◽  
Mahmoud Shaban ◽  
...  

Preparation of n-type β-FeSi2/intrinsic Si/p-type Si heterojunctions was accomplished by facing-target direct-current sputtering (FTDCS) and measuring their current-voltage characteristic curves at low temperatures ranging from 300 K down to 50 K. A mechanism of carrier transport in the fabricated heterojunctions was investigated based on thermionic emission theory. According to this theory, the ideality factor was calculated from the slope of the linear part of the forward lnJ-V plot. The ideality factor was 1.12 at 300 K and increased to 1.99 at 225 K. The estimated ideality factor implied that a recombination process was the predominant mechanism of carrier transport. When the temperatures decreased below 225 K, the ideality factor was estimated to be higher than two and parameter A was estimated to be constant. The obtained results implied that the mechanism of carrier transport was governed by a trap-assisted multi-step tunneling process. At high forward bias voltage, the predominant mechanism of carrier transport was changed into a space charge limit current process.


2013 ◽  
Vol 802 ◽  
pp. 199-203 ◽  
Author(s):  
Nathaporn Promros ◽  
Suguru Funasaki ◽  
Ryūhei Iwasaki ◽  
Tsuyoshi Yoshitake

n-Type nanocrystalline FeSi2/intrinsic Si/p-type Si heterojunctions were successfully fabricated by FTDCS and their forward current-voltage characteristics at low temperatures were analyzed on the basis of thermionic emission theory. The analysis of J-V characteristics exhibits an increase in the ideality factor and a decrease in the barrier height at low temperatures. The values of ideality factor were estimated to be 2.26 at 300 K and 9.29 at 77 K. The temperature dependent ideality factortogether with the constant value of parameter A indicated that a trap assisted multi-step tunneling process is the dominant carrier transport mechanism in this heterojunction. At high voltages, the current transport mechanism is dominated by SCLC process.


2013 ◽  
Vol 858 ◽  
pp. 171-176
Author(s):  
Nathaporn Promros ◽  
Ryūhei Iwasaki ◽  
Suguru Funasaki ◽  
Kyohei Yamashita ◽  
Chen Li ◽  
...  

n-Type NC-FeSi2/p-type Si heterojunctions were successfully fabricated by PLD, and their forward current-voltage characteristics were analyzed on the basis of thermionic emission theory (TE) in the temperature range from 300 down to 77 K. With a decrease in the temperature, the ideality factor was increased while the zero-bias barrier height was decreased. The calculated values of ideality factor and barrier height were 3.07 and 0.63 eV at 300 K and 10.75 and 0.23 eV at 77 K. The large value of ideality factor indicated that a tunneling process contributes to the carrier transport mechanisms in the NC-FeSi2 films. The series resistance, which was estimated by Cheungs method, was strongly dependent on temperature. At 300 K, the value of series resistance was 12.44 Ω and it was dramatically enhanced to be 1.71× 105 Ω at 77 K.


2013 ◽  
Vol 313-314 ◽  
pp. 270-274
Author(s):  
M. Faisal ◽  
M. Asghar ◽  
Khalid Mahmood ◽  
Magnus Willander ◽  
O. Nur ◽  
...  

Temperature dependent current-voltage (I-V) and capacitance-voltage (C-V) measurements were utilized to understand the transport mechanism of Pd Schottky diodes fabricated on Zn- and O-faces of ZnO. From I-V measurements, in accordance with the thermionic emission mechanism theory, it was found that the series resistance Rsand the ideality factor n were strongly temperature dependent that decreased with increasing temperature for both the faces (Zn and O-face) of ZnO revealing that the thermionic emission is not the dominant process. The barrier height øB(I-V)increased with increasing temperature for both faces. The measured values of ideality factor, barrier height and series resistance for Zn- and O-faces at room temperature were 4.4, 0.60 eV, 217 Ω and 2.8, 0.49 eV, 251 Ω respectively. The capacitance-voltage (C–V) measurements were used to determine the doping concentration Nd, the built-in-potential Vbi, and the barrier height øB(C-V). The doping concentration was found to be decreased with increasing depth. The barrier height øB(C-V)calculated for O-polar and Zn-polar faces decreases with increasing temperature. The values of barrier height øB(C-V)determined from C-V measurements were found higher than the values of barrier height øB(I-V). Keeping in view the calculated values of ideality factor, barrier height, and series resistance shows that O-polar face is qualitatively better than Zn-polar face.


2009 ◽  
Vol 23 (05) ◽  
pp. 765-771
Author(s):  
H. ESHGHI ◽  
M. MOHAMMADI

In this paper, the effect of porosity on reverse bias current–voltage characteristics of PtSi/por - Si (p-type) IR detector as a function of temperature is investigated. Our experimental data for two samples with different porosities (50% and 10%) at 300 K and 77 K are reported by Raissi et al.1 These data indicates a breakdown-like behavior. Our analytical model is based on hole thermionic emission with large ideality factor (n ≈ 200). Our calculations show that at each temperature, the Schottky barrier height, as well as the ideality factor, in sample with 10% porosity is bigger than that of 50%. These variations could be due to band gap variations of Si size effect using quantum dot model, and the presence of the relatively high (~1015 cm-2 eV-1) density of states at the silicide/por-silicon interface, respectively.


2014 ◽  
Vol 28 (13) ◽  
pp. 1450100
Author(s):  
Dil Nawaz Khan ◽  
Muhammad Hassan Sayyad ◽  
Fazal Wahab ◽  
Muhammad Tahir ◽  
Muhammad Yaseen ◽  
...  

This paper reports the temperature dependent electrical characterization of formyl- TIPPCu (II)/p- Si heterojunction diode which was fabricated by growing thin films of formyl- TIPPCu (II) on the p-type silicon substrate by thermal sublimation technique. The variation in electrical characteristics of the fabricated devices has been systematically investigated as the function of temperature by using current–voltage (I–V) measurements in the temperature range 299–339 K. The diode parameters like ideality factor, zero bias barrier height and parasitic series resistance have been found to be strongly temperature dependant. The zero bias barrier height increases while ideality factor and series resistance decreases with increasing temperature.


2015 ◽  
Vol 1098 ◽  
pp. 1-5 ◽  
Author(s):  
Thitinai Gaewdang ◽  
Ngamnit Wongcharoen

In this paper, p-CuO/n-CdS heterojunction was prepared by thermal evaporating CdS thin films on CuO 1 mm thick ceramic pellet substrate. The electrical properties of p-CuO/n-CdS heterojunction were investigated by forward current–voltage–temperature (I–V–T) characteristics in the temperature range of 100-300 K. The junction barrier height, ideality factor, and the series resistance values of the diode evaluated by using thermionic emission (TE) theory and Cheung’s method are 0.566 eV, 5.535 and 618.24 Ω at 300 K, respectively. The junction barrier height, ideality factor and series resistance were found to be strong temperature dependence. In part of C-V measurements at room temperature, the obtained built-in potential value being 0.538 V is well consistent with the junction barrier height value evaluated from I-V measurements


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