p-Si heterojunctions

Accepted Manuscript Solar light photodetectors based on nanocrystalline copper indium oxide/p-Si heterojunctions Najla M. Khusayfan, Ahmed A. Al-Ghamdi, F. Yakuphanoglu PII:

S0925-8388(15)31860-0

DOI:

10.1016/j.jallcom.2015.12.070

Reference:

JALCOM 36159

To appear in:

Journal of Alloys and Compounds

Received Date: 18 November 2015 Revised Date:

7 December 2015

Accepted Date: 8 December 2015

Please cite this article as: N.M. Khusayfan, A.A. Al-Ghamdi, F. Yakuphanoglu, Solar light photodetectors based on nanocrystalline copper indium oxide/p-Si heterojunctions, Journal of Alloys and Compounds (2016), doi: 10.1016/j.jallcom.2015.12.070. This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

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Solar light photodetectors based on nanocrystalline copper indium oxide/p-Si heterojunctions

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Najla M. Khusayfana , Ahmed A. Al-Ghamdib, F. Yakuphanoglu b,c a Physics Department, Faculty of Science- AL Faisaliah Campus, King Abdulaziz University, Jeddah, Saudi Arabia b Department of Physics, Faculty of Science, King Abdulaziz University, Jeddah, Saudi c Department of Physics, Faculty of Science, Firat University, Elazig, Turkey

Abstract

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Transparent conducting thin films of nanocrystalline copper indium oxide (CuInO2) having delafossite structure were synthesized using the sol-gel spin-coating method. Partial

xSnxO2

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substitution of In by Sn of varying percent weight realized films with the structure p-Si/CuIn1for x = 0, 0.01, 0.03, 0.05 and 0.07. Optical absorption measurements show that the

films have transmittance between 45% and 90% for visible and near infrared wavelengths and a direct band gap energy in the 3.83 eV to 3.93 eV range dependent on Sn content. The films

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exhibit a refractive index in the 1.2 to 1.4 range. Metalization of the composites using Al resulted in Schottky devices with the structure Al/p-Si/CuIn1-xSnxO2/Al which were investigated using direct current–voltage (I–V), photocurrent and impedance spectroscopy.

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The barrier heights showed low variance over illuminations and averaged 0.75, 0.72, 0.67, 0.74, 0.68 eV for x = 0, 0.01, 0.03, 0.05 and 0.07 of Sn. Capacitance–voltage (C–V)

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measurements suggest a continuous distribution of interface states over the frequency characterization range. The photocurrents were observed to increase with illumination intensity, with x = 0.03 showed the best photosensitivity over a wider range of applied reverse bias, the best photoresponse and the lowest series resistance (390Ω). The obtained results suggest that the performance of the photodiodes can be tuned by adjusting Sn content. Keywords:

Copper tin indium oxide, photodiode, photoresponse properties

Corresponding author: [email protected] (F.Yakuphanoglu) Tel:+90 424 2370000-3496 Fax:+90 424 233062

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ACCEPTED MANUSCRIPT 1. Introduction Transparent conducting oxides (TCOs) have been studied over the past- decades and continue to be a significant part of the optoelectronics research and industry [1-5]. They posses high optical transparency while maintaining good film conductivity. TCOs of the n-type such as Sn

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doped indium (III) oxide, Al doped tin oxide and Al doped zinc oxide have been well-studied and are reasonably developed. A persistent and urgent research is the quest for higher performing p-type transparent electrodes which tend to be the limiting aspect in the

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performance of some optoelectronic devices due to the low hole mobility of existing devices [5]. Copper-based delafossites, particularly CuInO2 [6, 7], have therefore generated much

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research interest in the past decade because they can be doped by metal atom substitution to either n-type (with Ca) or p-type (with Sn). These materials allow the engineering of rectifying homojunctions by controlling impurity concentration and deposition conditions [8]. It is thought that the monopolarity in present TCOs results from strong localization of positive

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holes at oxygen 2p levels or an upper edge of the valence band due to the strong electronegative nature of oxygen. It has been suggested that modification of the valence band edge by mixing orbitals of appropriate counter cations that have energy filled levels

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comparable to O 2p is effective to reduce the strong Coulomb force by oxygen ions and

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thereby delocalize positive holes. Many transparent p-type conducting delafossites and other conductive oxides are based on this suggestion [9 - 13]. CuInO2 has a special significance amongst transparent conductive oxides because it exhibits the widest band gap of 3.9 eV [8] although its electrical conductivity is generally lower. However, like many such oxides, it electrical conductivity can be tuned by the synthesis method. Yanagi et al 2001 [11, 12], for instance, have reported conductivities around 1 mS/cm using pulsed-laser deposition techniques from phase-pure CuInO2 precursors, whereas in comparison CuAlO2 has reported much higher conductivities ~300 mS/cm [10]. Sasaki et al [7] have suggested that the lower

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ACCEPTED MANUSCRIPT electrical conductivity observed of CuInO2 as compared with other delafossites could be due to higher valence band effective mass of CuInO2 than in other oxides. They show that the conduction band effective mass of CuInO2 is comparable in magnitude to other such oxides. In this paper, we report on the fabrication and characterization of Schottky diodes based on Sn

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substituted nanocomposites of CuInO2 delafossite brought out to a homojunction, which are observed to be rectifying. The diodes are fabricated with varied Sn weight in the nanocomposites and drop-cast onto a p-Si substrate. The resulting Schottky diodes have the

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structure Al/p-Si/CuIn1-xSnxO2/Al, where (
) is the weight fraction of Sn in the composite. The devices are characterized using I-V, transient photocurrent and photocapacitance

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methods. The results show that the device performances can be tuned through Sn content and the resulting devices have a clear potential in photosensing applications. 2. Experimental details

2.1. Synthesis of CuIn1_xSnxO2 films and preparation of the diodes

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The delafossite-oxide, CuIn1_xSnxO2 films having molar ratios of x = (0.00, 0.01, 0.03, 0.05, 0.07) were prepared using the sol–gel method. Firstly, the nominal values of copper acetate and anhydrous indium (III) nitrate were dissolved in 30 ml of anhydrous ethanol, and 5 ml of

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triethanolamine agent was added to the solution. The solution was stirred on a magnetic stirrer

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for 1 h, and then, stannous chloride was added to the solution for various Sn molar ratios. This solution was stirred for 10 h at 45 oC to solve completely. In order to prepare the diodes, ptype silicon wafers used and firstly, they were etched by HF to remove the native oxide layer of the silicon substrate and then rinsed in deionized water using an ultrasonic bath for 10 – 15 min. Finally, the silicon wafer was chemically cleaned by successive bathing in methanol and acetone. The ohmic contact to p-Si wafers was prepared by thermal evaporating of Al at 10-5 Torr. After the evaporation process, Al coated p-Si wafers were annealed at 570 oC for 5 min in nitrogen atmosphere. The solutions were spin-coated onto the p-Si substrates at 2000 rpm

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ACCEPTED MANUSCRIPT for 30 s and dried at 150 oC for 10 min. The obtained solid films on p-Si wafers having ohmic contacts were annealed in air in a tube-type annealing furnace at 500 oC. The chemical compositions of the films were studied using EDX spectroscopy. The optical transmission spectra were recorded at room temperature using a Shimazu UV-3600PC UV–VIS–NIR

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spectrophotometer in the 250–2500 nm wavelength range. Finally, the top contacts of the diodes were obtained by sputtering Al metal through a molybdenum mask with the dots of 1mm diameter (for 7.85x10−3 cm2 diode contact area). The electrical properties of the diodes

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were determined using the KEITHLEY 4200 semiconductor characterization system. Photoresponse measurements were performed using a solar simulator. Illumination intensity

3. Results and discussion

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was measured using a solar power meter (TM-206).

3.1. Structural and optical properties of CuIn1-xSnxO2 films

Figure 1 shows the SEM micrographs of the processed CuIn1-xSnxO2 (x = 0.00, 0.01, 0.03,

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0.05, 0.07) films deposited on p-Si substrates. The films initially exhibit textured spherical grains with a nanoparticle-like morphology below 3% Sn. At 3% the films show a continuous,

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well-textured profile with no clearly defined boundaries. For Sn content greater than 3% the

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films exhibit a higher density of grains of textured grains of smaller diameter. Figure 2

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ACCEPTED MANUSCRIPT (b) x=0.01

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(d) x=0.05

(e) x=0.07

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(c) x=0.03

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(a) x=0.00

Figure 1 SEM surface images of various Sn substitution ratios (x) in CuFe1-xSnxO2.

Figure 2 shows the typical EDS spectrum of the delafossite compound CuIn1-xSnxO2, using x = 0.03 as an example to show the elemental composition.

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Figure 2 Typical EDS spectrum of CuIn1-xSnxO2 given for x = 0.03 as an example.

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Figure 3 shows the absorbance (a), reflectance (b), transmittance (c) and refractive index (d) optical transmission characteristics and the allowed direct energy gap (e) in the UV–VIS–NIR region (250–2500 nm wavelength range) for the CuIn1-xSnxO2 thin films. The films exhibit good transparency in the visible and near-infrared wavelength regions. The 45 – 78%

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transmittance is much higher than previously reported for polycrystalline delafossite thin films [14, 15]. The NIR transmittance is found to be high at around 78 – 95%, confirming that the c-axis oriented films have better transparency compared with the polycrystalline thin films

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[5]. It is also apparent that doping with Sn ions decreases the NIR transmittance. This could

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be due to the formation of defect centers resulting from Sn2+. Such impurities can scatter incident photons and lead to decrease of transmittance. The optical band gap (Eg) of the film can be obtained using the following equation /   

(1)

where A is an energy-independent constant and E is the optical band gap [1, 16-18]. To determine optical band gaps of the films, we plotted the curves of (αhν)2 vs. hν, as shown in Figure 3e. The optical band gaps are determined to be 3.83 eV, 3.85 eV, 3.88 eV, 3.90 eV and

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ACCEPTED MANUSCRIPT 3.93 eV for Sn ratios of 0.00, 0.01, 0.03, 0.05, 0.07 respectively. The refractive index (Figure 3 (d)) was calculated from in the reflectance data in the absence of interference [19]. Figure 4 shows the Fourier transform infrared (FTIR) spectrum of the synthesized films. The FTIR plots show a characteristic shape of the predominant molecules in the samples regardless of

(b) Reflectance (%)

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(a) Absorbance (%)

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the doping content.

(c) Transmittance (%) (d) Refractive index

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(e) Plot of  versus 

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Figure 3 Optical characteristics of the as synthesized nanocomposite films of varying Sn weight.

Figure 4 Absorption Fourier transform infrared spectroscopy (FTIR) spectrum suggesting a characteristic molecular shape regardless of the Sn content.

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ACCEPTED MANUSCRIPT 3.2. Electrical and photoelectric properties of CuIn1-xSnxO2/p-Si diodes Figure 5 show I-V characteristics of the diode under different illuminations for various Sn doping concentrations. The analysis of I-V electrical characteristics was done using the method of Cheung & Cheung method that is well-covered in the literature [20-22]. Given that



  

  + 

!" #

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barrier height is Φ , ideality factor is  and resistance is  , then according to the method $

(2)

and

% ( 

(3)

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where

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%   + ∅'

!"

$ ln #



++∗ " -

$

(4)

In thermionic emission theory [23, 24], for a rectifying diode, the current at applied bias

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voltage (() and temperature (. is  / exp 3

#456  !"

7

(5)

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where / is the reverse saturation current:

#∅9 !"

$

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/ ∗ . 8 exp

(6)

where : is the electronic charge,  is device area and ; is Boltzmann constant. The effective Richardson’s constant, ∗ is 32A/cm8 K 8 for p-Si [25].

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(b) x=0.01

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(a) x=0.00

(c) x=0.03

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(d) x=0.05

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(e) x=0.07

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Figure 5 Illumination current-voltage characteristics of the CuIn1-xSnxO2 diodes for various Sn ratios x.

(b) x=0.00

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(a) x=0.00

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ACCEPTED MANUSCRIPT (d) x=0.01

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(c) x=0.01

(e) x=0.03

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(f) x=0.03

(h) x=0.05

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(g) x=0.05

(j) x=0.07

(i) x=0.07

Figure 6 Current-voltage illumination characteristics obtained using dV/d(LnI) and H(I) versus current method for different Sn concentrations.

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ACCEPTED MANUSCRIPT The distribution of interface states, which partly account for non unity ideality factors, can be investigated using photocurrent characterization methods. The photoconduction mechanism of the diodes can be analyzed by the following relation, AB CD

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(7)

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where AB is photocurrent, E is illumination coefficient and  is a constant [26, 27].

Figure 7 Plot of illumination exponents for different Sn content on the applied reverse bias range.

The E values for the diodes were determined and are shown in Figure 7. As seen in Figure 7,

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the E value is changed with Sn dopant. This indicates that the conduction mechanism of the

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diodes is changed from existence of a continuous distribution of localized states to the monomolecular mechanism. Table 1 summarizes the parameters of the studied Al/p-Si/CuIn1xSnxO2/Al

diodes over a wide range of illumination intensity. Although barrier height is

known to vary with illumination intensity [26], the observed coefficient of barrier height with illumination is negligible for the present diodes, as seen in Table 1. In Table 1 the calculated resistances of the two methods agree closely. It is reported in the literature that drift-diffusion analysis

of

charge-carrier

mobility

versus

illumination,

particularly

for

organic

semiconductors, shows pronounced charge carrier accumulation arising from poor transport 13

ACCEPTED MANUSCRIPT properties, a fact not taken into account in the Shockley equation. Recent work coins the term ‘interface states’ that lumps the phenomenon into a single term. For Schottky diodes intended primarily for photoconductive rather than photovoltaic (solar cell) application, high ideality factors and series resistance are not of much concern. In that case an illumination coefficient

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that is nearly constant with reverse bias is likely the more useful characteristic. The effects of series resistance and the true-space charge capacitance in the device are taken into account to obtain the corrected capacitance (F+GH ) and conductance (I+GH ) as follows [28] as

Q- MNOL -

- MNO - P JKL L

FR

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I+GH

- MNO - P JKL L

(8)

S

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F+GH

Q- MNOL -

(9)

8 where S IR TIR + UFR 8 V . Figure 8 and Figure 9 show the measured capacitance

and conductance and the series resistance adjusted capacitance and conductance of the diodes

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respectively.

Table 1 Al/p-Si/CuIn1-xSnxO2/Al diode parameters using the dV/d(LnI) and H(I) current-voltage methods.

x=0.00 Sn n

Dark

Φ (eV)

24.2

75

0.79

10

21.1

12

0.78

30

15.2

25

60

10.8

19

80

3.3

100

4.2

x=0.03 Sn

R (M)

Φ (eV)

n

1.49

114

1.05

25.6

1.8

0.74

34.9

0.73

25.8

19

0.73

12

0.72

x=0.05 Sn

x=0.07 Sn

R (k)

Φ (eV)

n

R (M)

Φ (eV)

n

R (k)

Φ (eV)

9.44

0.39

0.68

-

-

-

10.4

1.10

0.68

0.71

9.46

0.40

0.67

9.0

9.4

0.82

10.3

0.97

0.68

0.65

0.66

9.45

0.40

0.67

27.6

1.3

0.73

10.4

0.96

0.68

0.94

0.64

9.52

0.40

0.67

30.3

0.58

0.73

10.5

0.90

0.67

29.4

0.70

0.63

9.57

0.39

0.67

30.5

0.34

0.72

10.6

0.89

0.67

21.6

0.74

0.61

9.44

0.39

0.68

30.1

0.26

0.72

10.5

0.90

0.68

n

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R (M)

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P (mW/cm2)

x=0.01 Sn

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(b) x=0.00

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(a) x=0.00

(d) x=0.01

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(c) x=0.01

(f) x=0.03

(e) x=0.03

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(g) x=0.05

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(i) x=0.07

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(h) x=0.05

(j) x=0.07

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Figure 8Diode capacitance and conductance versus concentration and different characterization frequencies.

(b) x=0.00

(a) x=0.00

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(d) x=0.01

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(c) x=0.01

(e) x=0.03

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(f) x=0.03

(g) x=0.05

(h) x=0.05

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(k) x=0.07

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(l) x=0.07

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Figure 9 Series resistance adjusted capacitance and conductance of the diode versus concentration and different characterization frequencies.

The variations of resistance ( ) with applied bias voltage (() at different frequencies for different Sn content are shown in . The series resistance of the diodes is calculated using the equation [25, 26]

KL ⁄NOL -

IR

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MKL ⁄NOL -

(10)

The ( () plots exhibit peaks which shift towards higher positive bias voltage with

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frequency. The peaks intensity decrease with increasing frequency, suggesting that the

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interface states are frequency dependent. At lower frequencies the interface states can follow the AC signal resulting in excess capacitance. At higher frequencies the interface states cannot follow the AC signal and do not make a contribution to interface states [29, 30].

3.3. Transient photocurrents Figure 10 shows the diodes’ transient photocurrent as a function of illumination intensity measured at 10 kHz. When the illumination is turned on the photocurrent initially increases

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ACCEPTED MANUSCRIPT rapidly up to a certain level and then gradually reaches a peak value. After illumination is turned off the photocurrent decreases rapidly at first and then decays to its initial value. The increase in the photocurrent under illumination is due to the increase in the number of free charge carriers which contribute to the current. Similarly, after the illumination is turned off

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the decrease in the photocurrent reduces the current due to the trapping of the charge carriers

(b) x=0.01

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(a) x=0.00

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in the deep levels.

(c) x=0.03

(d) x=0.05

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(e) x=0.07

Figure 10 Transient photocurrents of the constructed Al/p-Si/CuIn1-xSnxO2/Al diodes at different Sn contents.

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Figure 11 shows that the fabricated devices exhibits a photocapacitive behaviour that depends on illumination intensity and Sn weight. The lowest photocapacitance was observed at 3% Sn.

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The figure suggests photocapacitance can be lowered by doping.

(b) x=0.01

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(a) x=0.00

(c) x=0.03

(d) x=0.07

Figure 11 Transient photocapacitance of the constructed Al/p-Si/CuIn1-xSnxO2/Al diodes at different Sn contents.

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4. Conclusions In this paper we have reported on the fabrication, optical characterization and application of c-

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axis orientated CuInO2 delafossite nanocomposite films on p-Si substrate with the partial substitution of In atoms using Sn. Metallization using Al metal realized a Schottky diode with the structure Al/p-Si/CuIn1-xSnxO2/Al. The device electrical parameters were then evaluated using current-voltage, capacitance-voltage and phototransient methods. These measurements

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show that the resulting Schottky diodes are sensitive to light, with tunable electrical responses by varying Sn content. The diode doped to x = 0.03 of Sn in the Al/p-Si/CuIn1-xSnxO2/Al

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composite exhibited the lowest series resistance. Considering only the plot of E versus (, the highest and most flat photocurrent response at given illumination over the applied voltage range was observed at 3% Sn doping. These results show that the presence of Sn in controlled weight can enhance the electro-optical performance of Schottky devices employing CuInO2

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Acknowledgements

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delafossites and lead to useful photoconducting devices.

Thanks are due to the Deanship of Scientific Research (DSR ) at King Abdulaziz University,

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Jeddah, Saudi Arabia, for facilitating and supporting the research group “Advances in composites, Synthesis and applications“. This work is as a result of international collaboration of the group with Prof. F. Yakuphanoglu and This study was supported by Fırat University Scientific Research Projects Unit Project numbers: FF.12.30 and FF.12.10.

References [1] R.K. Gupta, M. Cavas, F. Yakuphanoglu. Spectrochim. Acta, Part A. 95 (2012) 107–113 doi: 10.1016/j.saa.2012.04.012 21

ACCEPTED MANUSCRIPT [2] M.A. Ali, A. Khan, S.H. Khan, T. Ouahrani, G. Murtaza, R. Khenata, S. Bin Omran.. Mater. Sci. Semicond. Process. 38 (2015) 57–66. doi:10.1016/j.mssp.2015.03.038 [3] S.A. Mary, B.G. Nair, J. Naduvath, G.S. Okram, S.K. Remillard, P.V. Sreenivasan, R.R. Philip. J. Alloys Compd. 600 (2014) 159–161. doi:10.1016/j.jallcom.2014.02.113 Yu,

D.-H.

Hu.

Ceram.

Int.

41

doi:10.1016/j.ceramint.2015.03.313

(2015)

9383-9391.

RI PT

[4] R.-S.

[5] Y.-H. Chuai, B. Hu, Y.-D. Li, H.-Z. Shen, C.-T. Zheng, Y.-D. Wang. J. Alloys Compd.

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627 (2015), 299-306. doi: doi:10.1016/j.jallcom.2014.12.118

doi:10.1006/jssc.1999.8603

M AN U

[6] M. Shimode, M. Sasaki, K. Mukaida. J. Solid State Chem. 151 (2000) 16–20.

[7] M. Sasaki, M. Shimode. J. Phys. Chem. Solids. 64 (2003) 1675-1679. doi:10.1016/S00223697(03)00071-4

[8] S. Sohn, Y.S. Han. Transparent Conductive Oxide (TCO) Films for Organic Light

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Emissive Devices (OLEDs), Organic Light Emitting Diode - Material, Process and Devices, S.H. Ko (Ed.), ISBN: 978-953-307-273-9 (2011). [9] H. Yanagi, K. Ueda, S. Ibuki, T. Hase, H. Hosono, H. Kawazoe. Materials Science of

[10]

EP

Novel Oxide-Based Electronics, 623 (2000), 235-243, Code 58134 H. Yanagi, S.-I. Inoue, K. Ueda, H. Kawazoe, H. Hosono, N. Hamada. J. Appl. Phys.

[11]

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88 (2000), 4159-4163. doi: 10.1063/1.1308103 H. Yanagi, K. Ueda, H. Ohta, M. Hirano, H. Hosono. Materials Science of Novel

Oxide-Based Electronics, 666 (2001), F3141-F3146, Code 59226. [12]

H. Yanagi, T. Hase, S. Ibuki, K. Ueda, H. Hosono. Appl. Phys. Lett. 78 (2001), 1583-

1585; doi: 10.1063/1.1355673 [13]

H. Kawazoe, H. Yanagi, K. Ueda, H. Hosono. MRS Bulletin, 25 (2000) 28-36.

doi:10.1557/mrs2000.148.

22

ACCEPTED MANUSCRIPT [14]

H.Y. Chen, K.P. Chang, C.C. Yang, Appl. Surf. Sci. 273 (2013) 324–329.

[15]

H.Y. Chen, J.H. Wu, Thin Solid Films 520 (2012) 5029–5035.

[16]

Z. Deng, X. Fang, S. Wu, Y. Zhao, W. Dong, J. Shao, S. Wang, J. Alloys Comp. 577

(2013) 658–662. V.R. Shinde, T.P. Gujar, C.D. Lokhande, R.S. Mane, S.H. Han, Mater. Chem. Phys.

RI PT

[17]

96 (2006) 326.

F. Yakuphanoglu, B.F. Senkal, A. Sarac, J. Electron. Mater. 37 (2008) 930.

[19]

F. Padera. Measuring Absorptance (k) and Refractive Index (n) of Thin Films with the

SC

[18]

PerkinElmer Lambda 950/1050 High Performance UV-Vis/NIR

M AN U

PerkinElmer, Inc. Shelton, CT USA.

Spectrometers.

[20]

S.K. Cheung, N.W. Cheung, Appl. Phys. Lett., 85 (1) (1986).

[21]

D.T. Phan, R.K. Gupta, G.S. Chung, A.A. Al-Ghamdi, O.A. Al-Hartomy, F. El-

Tantawy, F. Yakuphanoğlu, Sol. Energy, 86 (2012) 2961–2966. R.O. Ocaya, A. Dere, H. Tuncer, A.A. Al-Ghamdi, D.C. Sari, F. Yakuphanoglu.

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[22]

Synth. Met. 209 (2015) 164–172. doi:10.1016/j.synthmet.2015.07.016 S.M. Sze, Physics of Semiconductor Device, Second ed., John Wiley & Sons, New

York, 1981. [24]

EP

[23]

E.H. Rhoderick, R.H. Williams, Metal–Semiconductor Contacts, Second ed.,

[25] [26]

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Clarendon Press, Oxford, 1988. R.K. Gupta, R.A. Singh, Mater. Chem. Phys., 86 (2004), 279–283.

M. Soylu, M. Cavas, A.A. Al-Ghamdi, Z.H. Gafer, F. El-Tantawy, F. Yakuphanoğlu,

Sol. Energy Mater. Sol. Cells, 124 (2014) 180–185. [27]

S. Kazim, V. Alia, M. Zulfequar, M.M. Haq, M. Husain, Physica B., 393 (2007), 310–

315. [28]

I. Dokme, S. Altindal, I. Uslu, J. Appl. Polym. Sci., (2012) DOI 10:1002/app.36327.

23

ACCEPTED MANUSCRIPT [29]

S. Karatas, A. Turut, Vacuum, 74 (2004) 45.

[30]

A. Tombak, Y.S. Ocak, S. Asubay, T. Kilicoglu, F. Ozkahraman, Mater. Sci.

AC C

EP

TE D

M AN U

SC

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Semicond. Process., 24 (2014) 187–192.

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ACCEPTED MANUSCRIPT 1. Sn doped Copper indium oxide/p-Si solar light photodetectors were fabricated. 2.

The diodes exhibited both photodiode and photocapacitor behavior.

AC C

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TE D

M AN U

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RI PT

3. The photodiodes can be used as a photosensor for optoelectronic applications.