Investigation of electrical properties of Ni/Crystal Violet (C25H30CIN3)/n-Si/Al diode as a function of temperature

(1)

Investigation of electrical properties of Ni/Crystal Violet (C

₂₅

H

₃₀

CIN

₃

)/

n-Si/Al diode as a function of temperature

Ali R

ıza Deniz

a,*

, Zakir Çald

ıran

b

, Mehmet Biber

c

, Ümit _Incekara

d

, S¸akir Aydogan

e a_{Department of Electric and Energy, Ç€olemerik V.H.S., Hakkari University, 30000, Hakkari, Turkey}

b_{Department of Electric and Energy, Ardahan Technical Sciences V.H.S., Ardahan University, 75000, Ardahan, Turkey} c_{Department of Biotechnology, Faculty of Sience, Necmettin Erbakan University, 42060, Konya, Turkey}

d_{Department of Biology, Faculty of Science, Atatürk University, 25240, Erzurum, Turkey} e_{Department of Physics, Faculty of Science, Atatürk University, 25240, Erzurum, Turkey}

a r t i c l e i n f o

Article history:

Received 9 November 2017 Accepted 24 May 2018 Available online 26 May 2018

Keywords: Crystal Violet Schottky diode Thermionic emission Norde Current-voltage Capacity-voltage

a b s t r a c t

In this study, Crystal Violet material was used for interface layer of Schottky diode applications. Firtly, chemical cleaning process have been made for boron doped n-Si crystals. After, Al metal was coated on the one surface of crystals by thermal evaporation and crystal violet materials were coated on other surface of crystals with spin coating method (coating parameters; 800 rpm for 60 s). Lastly, Ni metal was coated on Crystal Violet by sputtering. So, we obtained the Ni/Crystal Violet/n-Si/Al Schottky type diode. After the fabrication process of diode, the current-voltage (I-V) and capacity-voltage (C-V) measurements of Ni/Crystal Violet/n-Si/Al Schottky type diode were taken for various temperatures. The some basic diode parameters such as ideality factor (n), barrier height (Fb) and series resistance (Rs) of Ni/Crystal Violet/n-Si/Al were calculated from I-V measurements using different methods (Thermionic Emission, Cheung and Norde functions). Also, diode parameters such as Fermi energy level, diffusion potential, carrier concentration and barrier height were calculated from the C-V measurements of diode as a function of temperature.

1. Introduction

Crystal Violet is the primary stain used in the Gram stain tech-nique for differentiation of Gram-negative versus Gram-positive bacteria. Used as a component of CV cytotoxicity assays. Crystal Violet staining is commonly used for quanti_{ﬁcation of bioﬁlm} for-mation, although it is highly toxic [1,2].

Schottky diode applications very important for modern semi-conductor device technology. Schottky contacts play an important role in controlling the electrical performance of semiconductor devices.

These contacts are used in electronic and optoelectronic appli-cations such asﬁeld effect transistors (FETs), solar cells and pho-todetectors [3,4]. The characterization of the Schottky barrier is important not only because the Schottky diodes are the basic block of many semiconductor devices but because they may exhibit a

potential barrier at the metallization of a semiconductor surface for external device connection [5]. Schottky barrier height (SBH) is the most important parameter for Schottky diodes. The Schottky bar-rier height is very sensitive to the thermal treatment of the metal-semiconductor (MS) interfaces. Therefore, the fabrication of ther-mally stable Schottky contacts with high barrier height and low-reverse leakage current still up till now represents a challenge [6]. Schottky barrier diodes have been the subject of many exper-imental and theoretical studies due to their reliability and electrical properties [6]. Many of these studies are limited by the calculation of the barrier height from the current-voltage (I-V) and capacitanceevoltage (C-V) measurments of diode at room tem-perature. I-V and C-V characteristics (at room temperature) of diode not enough to explain the current transport mechanism. But, the temperature-dependent diode characteristics are very important to understand the dominant conduction mechanism [7,8]. In recti-fying contacts, to understand the barrier's nature and the conduc-tion mechanism, the main rectifying parameters such as the ideality factor n, the barrier height

F

band the series resistance Rs

should be determined, as a function of temperature. Rectifying devices often exhibit anomalous temperature dependence * Corresponding author. Tel: þ90 4382121212.

E-mail addresses: aliriza.deniz@atauni.edu.tr (A.R. Deniz), saydogan@atauni. edu.tr(S¸. Aydogan).

Contents lists available atScienceDirect

Journal of Alloys and Compounds

j o u r n a l h o m e p a g e : h t t p : / / w w w . e ls e v i e r . c o m / l o c a t e / j a l c o m

https://doi.org/10.1016/j.jallcom.2018.05.295

(2)

behavior that could be evidenced by these parameters [8,9]. The determination of the I-V characteristics of diode based on Therm-ionic Emission (TE) theory. According to TE theory, ideality factor increases and barrier height decreases with the decreasing tem-perature. This can be attributed to quantum-mechanical tunneling, the distribution of the interface state density, image-force lowering (Schottky effect) and, especially, the lateral a Gaussian distribution of barrier height in homogeneities [10,11]. In this, study we inves-tigate the temperature-dependent current-voltage (I-V) and capacitance-voltage (C-V) characteristics of the Ni/Crystal Violet/n-Si/Al Schottky diode in the temperature range of 200 Ke340 K in steps of 20 K. The temperature dependence of basic diode param-eters such as series resistance, barrier heights, ideality factor, donor concentration, Fermi energy level and diffusion potential are discussed.

2. Experimental procedure

In this study, an n-type Si semiconductor wafer with (100) orientation, 400

m

m thickness and 1-10

U

-cm resistivity was used. Firstly, the wafer was carefully chemically cleaned in acetone and methanol. Then, the n-Si wafer was chemically cleaned using the RCA cleaning procedure (i.e. 10 min boiling in NH3þH2O2þ6H2O

followed by 10 min in HClþ H2O2þ6H2O at 60C) before making

contacts [12,13]. After the cleaning process, ohmic contact was made by evaporating Al metal on the back of the wafer at 105Torr, and was then annealed at 450C for 10 min in an N2atmosphere.

The native oxide on the front surface of the n-Si substrate was removed in HFþ 10H2O solution at before forming a Crystal Violet

layer on the Si substrate. Later, Crystal Violet was dissolved in deionized water to make 0.5 mg/1 ml solution and an organic Crystal Violet layer formed on other surface of n-Si by spin coating method with 800 rpm, 60 s in clean rooms (class 1000). Finally, Ni was coated by DC sputtering method on Crystal Violetﬁlm at 105

torr pressure and hence, we obtained device shown inFig. 1a and the chemical structure of Crystal Violet is depicted inFig. 1b. The IeV and CeV measurements of the diode have been performed with KEITHLEY 487 Picoammeter/Voltage Source and HP 4192A (50 Hze13 MHz) LF IMPEDANCE ANALYZER, respectively. All elec-trical measurements have been performed at various temperatures.

3. Results and discussion

Current-voltage (I-V) measurements are one of the most com-mon methods to determine the transport mechanism in junction diodes. According to the Thermionic Emission (TE) theory, the current in Schottky barrier diodes (SBDs) can be expressed as: I¼ I0 exp eV nkT 1 (1) where Iois given by;

Io¼ AA*T2exp q

F

b kT ; (2)

and it is determined from the intercept of lnI vs. V curve on the y-axis. A is the effective diode area, A* is the Richardson constant of semiconductor and it equals to 112 A/cm2K2for n-type Si [12,14], T is the temperature (in Kelvin),

F

bis the effective barrier height at

zero bias, q is the electron charge, V is the bias voltage, k is the Boltzmann constant, n is the ideality factor. The ideality factor n is calculated from the slope of the forward I-V characteristics through the relation: n¼ 1 c2¼ q kT dV dð[nIÞ (3)

and the value of the barrier height (BH) is determined as: q

F

b¼ kT ln

AA*T2.I0

(4) Ideality factor; is a very important parameter that determines the character of the diode. For an ideal diode n_{¼ 1 and as the value} of n goes away from 1, the diode exhibits non-ideal behavior [3,15]. In general, in practice, the ideality factor has a value greater than 1. The reason for the large value of the ideality factor is attributed to the existence of a thin natural interface oxide layer and series resistance. However, non-homogeneous barrier height leads to higher ideality factor value [16]. At the same time, the higher ide-ality factor may be due to the presence of secondary mechanisms such as interface dips and interfacial fabrication defects caused by an organic interlayer or a particular interface structure [17].

Fig. 2 shows the I-V characteristic of Ni/Crystal Violet/n-Si/Al SBD in the temperature range of 200 Ke340 K by steps of 20 K. Using the TE for Ni/Crystal Violet/n-Si/Al SBDs, the experimental values of

F

band n were determined from the current axis intercept

and the slope of the linear region of the forward bias lnIeV char-acteristics at each temperature.Table 1shows the basic diode pa-rameters of this diode that obtained by the thermionic emission method depending on the temperature.Fig. 3shows the variation of the ideality factor with temperature andFig. 4shows the vari-ation of the barrier height value with temperature. As seen from the tables andﬁgures, when the temperature increases, the value of the ideal factor decreases, and the value of barrier height increases. Since the current conduction at the metal-semiconductor interface depends on the temperature, electrons encounter a lower barrier at lower temperatures, the current conduction is dominant and the value of the ideal factor increases [10,18]. In this work, the greatest Fig. 1. a. Schematic diagram of Ni/Crystal Violet/n-Si/Al Schottky diode. b. The chemical diagram of Crystal Violet.

(3)

ideal factor values are attributed to secondary mechanism at the interface of Crystal Violet and the lateral non-homogeneous dis-tribution of the barrier height which interface defects can create [19]. As the temperature increases, the electrons will have enough energy to overcome a higher barrier, and as a result the barrier height will increase depending on the temperature and the bias supply voltage. Also deviations of barrier height and ideality factor wit temperature usually caused surface defects in the interface, high interface state density due to interface contamination and non-homogeneous doping concentration [20,21].

Series resistance is an important parameter for explaining to electrical properties of diode, and it is inﬂuenced by the presence of the interface layer. The presence of the higher values of Rsreduces

the performance of the devices. So, it gives a non-ideal forward bias I-V curve. The series resistance can be extracted from the forward biased diode for high voltages through Cheung functions [22]. Cheung functions were used for calculation of ideality factor, bar-rier height and series resistance values of Ni/Crystal Violet/n-Si/Al diodes between 200 K and 300 K. According to the Cheung method, the large forward-bias (V>3kT/q) IeV characteristics from the TE model of a Schottky diode which has a series resistance can be given as Equation(5). Where the IRs term indicates the voltage drop across the series resistance of the diode described in the equation. The series resistance values can be determined from Equations(6) and (8)as: I¼ I0exp qðV IRsÞ nkT ; (5) dV dðln IÞ¼ nkT q þ IRs; (6) HðIÞ ¼ V nkT q ln I AA*T2 ; (7)

and HðIÞ is given as follows:

HðIÞ ¼ n

F

bþ IRs (8)

The series resistance value (Rs) can be calculated from the slope

of the dV/d(lnI) - I plots, and nkT/q are obtained at the interception of the y-axis, as indicated by Equation(6).Fig. 5shows the relations between dV/d(lnI) and I as a function of temperature. Also,Fig. 6

shows the relations between H (I) and I as a function of tempera-ture. Table 2 gives ideality factor, series resistance and barrier height values of Ni/Crystal Violet/n-Si/Al diode which calculated using Cheung functions. The barrier height values calculated by Cheung and Thermionic Emission methods are similar to each other. The correspondence between barrier height values is shown Fig. 2. The currentevoltage characteristics of Ni/Crystal Violet/n-Si/Al SBD in the

temperature range of 200e340 K.

Table 1

Ideality factor and barrier height values of Ni/Crystal Violet/n-Si/Al SBD as a function of temperatures.

Temperature (K) Ideality Factor (n) Barrier Height (eV)

340 1,17 0,81 320 1,31 0,79 300 1,38 0,74 280 1,60 0,70 260 1,83 0,68 240 2,10 0,62 220 2,42 0,59 200 2,64 0,53

Fig. 3. Ideality factor values of Ni/Crsytal Violet/n-Si/Al diode as a function of temperature.

(4)

inFig. 7. As seenFig. 8, there is a difference for the ideality factor values obtained from the forward-bias lnIeV and from the dV/d(ln I)eI plots. This can be explained by the existence of a high series resistance Rs, the interface states and the voltage across the

inter-facial layer of the device [22,23].Fig. 9shows the change of series resistance values of Ni/Crystal Violet/n-Si/Al diode with tempera-ture. As can be seen from theseﬁgure, the series resistance values obtained from the curve dV/d (lnI) - I and the curve H (I) -I are compatible with each other. It is also seen that as the temperature increases, the series resistance values decrease. Increase of series resistance values with decrease of temperature; can be interpreted as a consequence of increased free carrier density by ionization at high temperatures [4,24].

Norde function is an another important method for the deter-mination of series resistance and barrier height values [25]. The Norde function is deﬁned as:

FðVÞ ¼V

_g

kT 2 In IðVÞ AA*T2 (9) whereɣ is an integer greater than the ideality factor, and I(V) is current obtained from the I-V curve. The basic technique of Norde method is to plot the proposed function with respect to voltage applied across the SBD, and to obtain its minimum value. First the minimum of the F(V) versus V plot is determined and the value of barrier height can be calculated using the following equation:

F

b¼ FðV0Þ þ

V0

2 kT

q (10)

where F(V0), V0,I0are the minimum value of F(V), the corresponding

voltage and current, respectively. According to the Norde function, the value of series resistance can be calculated using the following equation:

R_s¼kTð

g

_qI nÞ

o (11)

Fig. 10shows the plot of F(V) versus of V of Ni/Crystal Violet/n-Si/ Al diode. According to this graph, there is a compatible change between F(V) and V with increasing temperature. The barrier height and series resistance values of diode were calculated with Norde functions and these values are given inTable 3. The temperature dependence of the series resistance of diode is shownFig. 11. The series resistance value decreasing with the increasing temperature. Fig. 4. Barrier height values of Ni/Crsytal Violet/n-Si/Al diode depending on

temperature.

Fig. 5. The plots of dV/d(lnI) versus I obtained from forward bias currentevoltage characteristics of the Ni/Crystal Violet/n-Si/Al Schottky barrier diode.

Fig. 6. The plots of H(I) versus I obtained from forward bias currentevoltage charac-teristics of the Ni/Crystal Violet/n-Si/Al Schottky barrier diode.

(5)

Decreasing series resistance with the increasing temperature is originated the lack of free carrier concentration [26]. Additionally, the comparison of series resistance values obtained from Cheung and Norde functions are shown inFig. 11, too. There is a similarity between the series resistance values calculated from dV/dlnI-I and H(I)-I curves. However, series resistance values obtained from Norde function is much greater than obtained from Cheung func-tions. While Cheung model is applied to high voltage area of for-ward bias lnI-V, Norde function is applied to all voltage area of diode [27]. Also, this difference may be due to the Crystal Violet layer, which modiﬁes the

F

bby inﬂuencing the space charge region of the

n-Si inorganic substrate [25].

C-V measurements were taken for Ni/Crystal Violet/n-Si/Al at a temperature range of 340 Ke200 K and a frequency of 500 kHz. Also, this measurements were performed between2 V and 2 V. Metal-semiconductor contacts are like a capacitor. Thus, taking C-V measurements gives important information about the formation of the metal-semiconductor interface. The diode parameters such as the barrier height of the rectiﬁer contact, the carrier concentration in the semiconductor, the diffusion potential and the Fermi energy level are calculated from the capacitance-voltage graph in the case of reverse bias.Fig. 12represents the experimental reverse bias C_eV characteristics of the Ni/Crystal Violet/n-Si/Al Schottky contacts over the temperature range of 200e340 K in steps of 20 K. These plots Show that the capacitance is strongly dependent on voltage

and temperature. Particularly, the values of capacitance are higher at the high temperatures with respect to the low temperatures. This behavior can be explained by the freeze-out of trapping and de-trapping phenomena at interface states acting as recombination centers Also, this can be attributed to that ionization process is too slow to follow the applied sinusoidal voltage [28].Fig. 13is given C2-V characteristics of diode as a function of temperature. In

Fig. 13, the characterization of C2-V variations have not Table 2

The values of series resistance, barrier height and ideality factor of Ni/Crystal Violet/ n-Si/Al diode have been calculated by the Cheung Functions and Thermionic Emission Method.

Temperature (K) I-V dV/d(lnI)-I H(I)-I

n Fb(eV) n Rs(U) Fb(eV) Rs(U) 340 1,17 0,81 1,91 2154 0,78 1986 320 1,31 0,79 2,23 2847 0,71 2594 300 1,38 0,74 2,54 3578 0,65 3007 280 1,60 0,70 3,17 4019 0,59 3745 260 1,83 0,68 3,88 5122 0,53 4602 240 2,10 0,62 4,09 6958 0,49 6111 220 2,42 0,59 4,46 8554 0,47 7890 200 2,64 0,53 4,91 10270 0,43 9236

Fig. 7. Change graph of barrier height values with temperature which calculated using Cheung and Thermionic Emission method.

Fig. 8. Change graph of ideality factor values with temperature which calculated using Cheung and Thermionic Emission method.

Fig. 9. Change graph of series resistance values with temperatures which obtained from the plots of dV/d(lnI) versus I and the plots of H(I) versus I.

(6)

demonstrated a rapid variation with temperature and the variation of C2-V have well linearization for all temperatures. It indicates that diode have uniform dopant concentration. The depletion layer capacitance for an abrupt Schottky junction is given by the expression 1 C2 r ¼ 2 ε0qNdA2 ðVbi VÞ (12)

where Vbiis built in potential, Ndis donor concentration,ε0is the

permittivity of the semiconductor, A is diode area. The intercept of 1=C2

r versus V on the ordinate gives Vbi.The barrier height

F

bis

given by

F

b¼ Vbiþ Ef (13) Ef ¼ kT q ln N_d Nc (14) Nc is the density of state in the conductivity band edge. The

value of Ncis 2,8 1019cm3for n-Si at the room temperature. As a

function of temperature, values of barrier height, Fermi energy level, donor concentration and diffusion potential are givenTable 4. The values of Ndwere calculated to be (0,99e1,53)x1013cm3in the

temperature range of 200e340 K, respectively. The variation of Nd

depending on the temperature could be attributed to the modu-lation of space charge region caused by the emission of more car-riers from the deep-level impurities at higher temperatures [4,7,29]. The values of

F

b at different temperatures are listed in Table 4, showing the barrier height

F

_b decreases with the increasing of temperature. The differences in the barrier height determined from I-V and C-V measurements are due to the in-homogeneity in the interfacial layer composition, non-uniformity Fig. 10. F(V) versus V plot of the Ni/Crystal Violet/n-Si/Al diode.

Table 3

The values of series resistance and barrier heights which calculated using Norde functions.

Temperature (K) Series Resistance (U) Barrier Height (eV)

340 2455 0,85 320 3609 0,81 300 4198 0,77 280 5106 0,73 260 6395 0,70 240 7344 0,66 220 9808 0,61 200 11833 0,57

Fig. 11. Comparison of series resistance values obtained from Cheung and Norde functions.

Fig. 12. C-V characteristics of Ni/Crystal Violet/n-Si/Al Schottky diode as a function of temperature.

(7)

of the interfacial layer thickness, and the distribution of interface charges [7,30].

4. Conclusions

As a result, Ni/Crystal Violet/n-Si/Al diode were fabricated. The forward bias I-V-T and C-V-T characteristics of this diode have been systematically investigated over the temperature range 340 Ke200 K with steps 20 K. The basic diode parameters such as n,

F

band Rswere calculated from forward bias of I-V measurements.

These values have been shown strong temperature dependence. The increase in the ideality factor and decrease in the barrier height with decrease in temperature in the Ni/Crystal Violet/n-Si/Al diode has been analyzed on the basis of the Thermionic emission theory. Also, the series resistance value decreases with increase tempera-ture. This behavior is attributed to the Schottky barrier in-homogeneities by assuming a Gaussian distribution of barrier height due to barrier inhomogeneities that prevails at interface. From the C-V measurements, the value of barrier height calculated and there was a difference between barrier height values which are obtained I-V and C-V data. The difference is attributed to Schottky barrier inhomogeneity and the large potentialﬂuctuations existing in its barrier structure.

References

[1] P. Ommen, N. Zobek, R.L. Meyer, Quantiﬁcation of bioﬁlm biomass by staining: non-toxic safranin can replace the popular crystal violet, J. Microbiol. Meth. 141 (2017) 87e89.

[2] P.M. Parameshwari, et al., Electrical behavior of CdS/Al Schottky barrier diode at low temperatures, Mater. Today Proc. 3 (6) (2016) 1620e1626.

[3] E. Ozerden, et al., Electrical and photoelectrical properties of Ag/n-type Si metal/semiconductor contact with organic interlayer, Thin Solid Films 597 (2015) 14e18.

[4] I. Jyothi, et al., Currentevoltage and capacitanceevoltage characteristics of Al Schottky contacts to strained Si-on-insulator in the wide temperature range, Mater. Sci. Semicond. Process. 39 (2015) 390e399.

[5] W. Filali, et al., Characterisation of temperature dependent parameters of multi-quantum well (MQW) Ti/Au/n-AlGaAs/n-GaAs/n-AlGaAs Schottky di-odes, Superlattice. Microst. (2017).

[6] A. Ashok Kumar, et al., Analysis of electrical characteristics of Er/p-InP Schottky diode at high temperature range, Curr. Appl. Phys. 13 (6) (2013) 975e980.

[7] J. Chen, et al., Currentevoltageetemperature and capaci-tanceevoltageetemperature characteristics of TiW alloy/p-InP Schottky bar-rier diode, J. Alloys Compd. 649 (2015) 1220e1225.

[8] I. Jyothi, et al., Temperature-dependent currentevoltage characteristics of Er-silicide Schottky contacts to strained Si-on-insulator, J. Alloys Compd. 556 (2013) 252e258.

[9] A. Tataroglu, S¸. Altındal, The analysis of the series resistance and interface states of MIS Schottky diodes at high temperatures using IeV characteristics, J. Alloys Compd. 484 (1e2) (2009) 405e409.

[10] Y. Li, W. Long, R.T. Tung, Effect of metal interaction on the Schottky barrier height on adsorbate-terminated silicon surfaces, Appl. Surf. Sci. 284 (2013) 720e725.

[11] W. Long, Y. Li, R.T. Tung, Schottky barrier height systematics studied by partisan interlayer, Thin Solid Films 557 (2014) 254e257.

[12] O. Pakma, et al., Improvement of diode parameters in Al/n-Si Schottky diodes with Coronene interlayer using variation of the illumination intensity, Phys. B Condens. Matter 527 (2017) 1e6.

[13] P.R.S. Reddy, et al., Microstructural and electrical properties of Al/n-type Si Schottky diodes with Au-CuPc nanocompositeﬁlms as interlayer, Superlattice. Microst. 111 (2017) 506e517.

[14] S. Rahmatallahpur, M. Yegane, Effect of nanopatches on electrical behavior of Ni/n-type Si Schottky diode, Phys. B Condens. Matter 406 (8) (2011) 1351e1356.

[15] D. Korucu, S. Duman, Currentevoltageetemperature characteristics of Au/p-InP Schottky barrier diode, Thin Solid Films 531 (2013) 436e441.

[16] K. Çınar, et al., Electrochemical growth of GaTe onto the p-type Si substrate and the characterization of the Sn/GaTe Schottky diode as a function of temperature, Thin Solid Films 550 (2014) 40e45.

[17] V.R. Reddy, Electrical properties of Au/polyvinylideneﬂuoride/n-InP Schottky diode with polymer interlayer, Thin Solid Films 556 (2014) 300e306. [18] <1-s2.0-S0927796X01000377-main tung 2.pdf>.

[19] D. Korucu, A. Turut, H. Efeoglu, Temperature dependent IeV characteristics of an Au/n-GaAs Schottky diode analyzed using Tung's model, Phys. B Condens. Matter 414 (2013) 35e41.

[20] H. Dogan, S. Elagoz, Temperature-dependent electrical transport properties of (Au/Ni)/n-GaN Schottky barrier diodes, Phys. E Low Dimens. Syst. Nanostruct. 63 (2014) 186e192.

[21] S.M. Tunhuma, et al., The effect of high temperatures on the electrical char-acteristics of Au/n-GaAs Schottky diodes, Phys. B Condens. Matter 480 (2016) 201e205.

[22] €O.F. Yüksel, et al., Electrical properties of Au/perylene-monoimide/p-Si

Schottky diode, J. Alloys Compd. 577 (2013) 30e36.

[23] X. Zhang, et al., Fabrication and characterization ofﬂexible Ag/ZnO Schottky diodes on polyimide substrates, Thin Solid Films 548 (2013) 623e626. [24] N. Hamdaoui, et al., Distribution of barrier heights in metal/n-InAlAs Schottky

diodes from currentevoltageetemperature measurements, Mater. Sci. Semi-cond. Process. 26 (2014) 431e437.

[25] €O. Tüzün €Ozmen, E. Yaglıoglu, Electrical and interfacial properties of Au/P3HT:

PCBM/n-Si Schottky barrier diodes at room temperature, Mater. Sci. Semi-cond. Process. 26 (2014) 448e454.

[26] S. Hussain, et al., Cu2O/TiO2 nanoporous thin-ﬁlm heterojunctions: fabrica-tion and electrical characterizafabrica-tion, Mater. Sci. Semicond. Process. 25 (2014) 181e185.

[27] H.-K. Lee, et al., Effects of Ta-oxide interlayer on the Schottky barrier pa-rameters of Ni/n-type Ge Schottky barrier diode, Microelectron. Eng. 163 (2016) 26e31.

[28] T. Çakıcı, B. Güzeldir, M. Saglam, Temperature dependent of electrical char-acteristics of Au/n-GaAs/In Schottky diode with in 2 S 3 interfacial layer ob-tained by using spray pyrolysis method, J. Alloys Compd. 646 (2015) 954e965. [29] M. Gülnahar, Temperature dependence of current-and capacitanceevoltage characteristics of an Au/4H-SiC Schottky diode, Superlattice. Microst. 76 (2014) 394e412.

[30] M. Gülnahar, H. Efeoglu, M. S¸ahin, On the studies of

capacitance-voltage-temperature and deep level characteristics of an Au/p-GaTe Schottky diode, J. Alloys Compd. 694 (2017) 1019e1025.

Fig. 13. C2-V characteristics of Ni/Crystal Violet/n-Si/Al Schottky diode as a function of temperature.

Table 4

The values of donor concentration, diffusion potential, Fermi energy level and bar-rier heights depend on temperature that calculated by C2-V characteristics of Ni/ Crystal Violet/n-Si/Al.

Temperature (K) Vd(V) Ef(eV) Nd(cm3) 1013 Fb(eV)

340 0,05 0,34 1,53 0,77 320 0,14 0,32 1,49 0,74 300 0,28 0,30 1,43 0,71 280 0,41 0,29 1,42 0,68 260 0,56 0,30 1,38 0,53 240 0,61 0,28 1,27 0,59 220 0,63 0,27 1,08 0,54 200 0,75 0,21 0,99 0,50