The investigation of the electrical characteristics and photo-response properties of the Al/(CMAT)/p-Si structures

https://doi.org/10.1016/j.solidstatesciences.2021.106635Get rights and content

Highlights

  • The Al/(CMAT)/p-Si photodiode was fabricated by thermal evaporation.

  • The photoconductivity mechanism and the transient photocurrent-time of the Al/(CMAT)/p-Si photodiode were analyzed.

  • The electrical properties of the Al/(CMAT)/p-Si photodiode were examined at various temperatures and frequencies.

  • The photodiode can be used in optoelectronic applications.

Abstract

In this study, the electrical and photo-response characteristics of the Al/(CMAT)/p-Si photodiode (the device) were reported. The photodiode properties of the device were examined under various illumination intensities at room temperature. It was observed that the prepared device has a good response to the illumination. The photoconductivity mechanism (PM) of the device at −2 V was examined and the slope of the PM was found to be 0.774. Also, the transient photocurrent-time (TPT) of the device was analyzed with the switching light on (100 mW/cm2) and switching the light off (dark). The experimental results of PM and TPT showed that the prepared device may be used in optoelectronic as well as photovoltaic applications. Furthermore, the dependent-temperature electrical properties were analyzed using the current (I)-voltage (V) measurement at various temperatures (90 K, 210 K, and 340 K) while the dependent-frequency electrical properties were analyzed using the capacitance-voltage (C–V) and the conductance-voltage (G/ω-V) data at various frequencies (4 kHz, 400 kHz, and 4 MHz). Since the interface states (Nss) affect the electrical parameters of the device, the Nss values of the device were examined using the high-low frequency capacitance (CLF-CHF) method. Additionally, the morphological properties of the CMAT film were examined using AFM and the root-mean-square (RMS) roughness value of the films was found to be 31.19 nm.

Introduction

A wide variety of device applications such as photodiode [1], solar cell [2], and Schottky diode [3] are commonly used in electronic and optoelectronic technology. The common feature of these device applications has an interface layer between the metal (M) and the semiconductor (S). The performance of these devices depends on many physical factors such as temperature, frequency, illumination intensity, interlayer at M/S interface and its permittivity, and the fabrication process [[4], [5], [6]]. The interface layer is used to improve the performance of devices. Additionally, the thickness of the layer and its dielectric constant affect significantly the main parameters such as the efficiency of the devices, current conduction mechanisms and ideality factor (n), barrier height (ΦB0), series resistance (Rs). Thus, the selection of the layer should be optimal. For instance; Li et al. [7] examined the barrier height of the Ti/n-Ge diodes with different thicknesses of Y2O3 at room temperature and they stated that the optimum thickness for the interface layer of the diode could be about 1 nm. Gezgin et al. [8] examined the electrical properties of structures with different thicknesses of Copper Zinc Tin Sulphur (CZTS)/Si interfaces under illumination conditions and they showed that the thickness with the best electrical properties could be at 210 nm.

Photodiodes, a type of semiconductor device, convert the light into current. Additionally, photodiodes are used to detect light at the various spectral regions such as visible, UV, and IR. In recent years, researchers have focused on improving the electrical and optical properties, performance, and quality of photodiodes with various interface layers [[9], [10], [11], [12], [13], [14], [15]]. Aydın et al. [10] fabricated Au/LiZnSnO/p-Si/Al photodiodes and they analyzed the electrical characteristics of the photodiodes by I–V, C–V, and G/ω-V measurements. Esteves et al. [13] fabricated SnOx and a-Si based p-i-n flexible photodiode and they studied photodiode responsivity at various wavelengths and photodiode response times. Koksal et al. [16] fabricated ZnO:Ga (GZO)/Si photodiodes having different thicknesses of GZO layer by using the sol-gel spin-coating method. They investigated the photoelectric properties of the ZnO:Ga (GZO)/Si photodiodes.

The materials such as polymer [17], organic [18], ferroelectric [19], and Rare earth elements (REEs) [20] were used as the interface layer in the literature. However, the use of REEs-doped materials as an interface layer is very rare in the literature. REEs are composed of seventeen chemical elements with atomic numbers from 57 to 71 [21]. REEs are widely used in many innovative implements such as photovoltaics, laser, and superconductive materials because of their optical and electrical properties [[22], [23], [24], [25]]. Among REEs, Terbium (Tb) is used in phosphors for solid-state lighting [25] and it is the main ingredient of magnetostrictive materials [26]. Tb is the least abundant of the REEs in terms of abundance in nature [21].

In this study, CeMgAl11O19:Tb (CMAT) was used as the interface layer between M and S. The present article has been reported that the effect of the CMAT interfacial layer on electrical and photo-response properties of Schottky diodes was investigated. The photo-response properties of the Al/(CMAT)/p-Si photodiode were examined at various illumination intensities. The photoconductivity mechanism (PM) and the transient photocurrent-time (TPT) of the device were analyzed at −2 V. Additionally, the ideality factor (n), barrier height (ΦB0), saturation current (I0) and series resistance (Rs) of the device at various temperatures were examined by using the I–V measurement. The Fermi Level (EF), depletion layer width (WD), diffusion potential (VD), acceptor concentration (NA), and barrier height [ΦB(C–V)] were calculated by using intercept and slope of C−2-V plot measurements in various frequencies.

Section snippets

Experimental procedures

The preparation of the Al/(CMAT)/p-Si Schottky Diodes was implemented in four steps. (i) Boron-doped p-Si crystal (1–10 Ω cm resistivity, (101) orientation and 500-μm thickness) was cleaned in an ultrasonic bath for 5 min using acetone, isopropanol, and deionized water, respectively. Then, the crystal was dried with nitrogen (N2). Hydro-fluoride (HF) (20:1) was used to eliminate the native oxide layer and contamination on the surface. Then, the wafer rinsed with high-pure deionize water for

The surface analysis of the device

There are various methods such as further increasing the light absorption, improve the electron transfer, and surface modification to increase the charge carriers that determine the photo-response properties of structures [27]. The thickness (δi) and surface morphology of the interface layer is one of the most important parameters in determining the electrical properties of structures such as solar cell and photodiode [[27], [28], [29]]. Such an interfacial layer with optimum surface morphology

Conclusions

The electrical characteristics of the Al/(CMAT)/p-Si photodiode were reported at various illumination intensity, temperatures, and frequency conditions. The photodiode properties of the device were examined using the photoconductivity mechanism (PM) and the transient photocurrent-time (TPT) mechanisms. It was seen from the PM and TPT results that the prepared device showed photosensitivity behavior. Additionally, the experimental results showed that the prepared photodiode can be used in

Declaration of competing interest

No conflict of interest exists.

References (76)

  • W. Pei et al.

    Enhanced photovoltaic effect in Ca and Mn co-doped BiFeO3 epitaxial thin films

    Appl. Surf. Sci.

    (2020)
  • Z. Chen

    Global rare earth resources and scenarios of future rare earth industry

    J. Rare Earths

    (2011)
  • H. Javadian et al.

    Novel magnetic nanocomposite of calcium alginate carrying poly(pyrimidine-thiophene-amide) as a novel green synthesized polyamide for adsorption study of neodymium, terbium, and dysprosium rare-earth ions

    Colloid. Surface. Physicochem. Eng. Aspect.

    (2020)
  • S. Sönmezoğlu et al.

    Fast production of ZnO nanorods by arc discharge in de-ionized water and applications in dye-sensitized solar cells

    J. Alloys Compd.

    (2014)
  • H.G. Çetinkaya et al.

    The fabrication of Al/p-Si (MS) type photodiode with (%2 ZnO-doped CuO) interfacial layer by sol gel method and their electrical characteristics

    Phys. B Condens. Matter

    (2019)
  • A. Tataroğlu et al.

    60Co γ irradiation effects on the current–voltage (I–V) characteristics of Al/SiO2/p-Si (MIS) Schottky diodes

    Nucl. Instrum. Methods Phys. Res. Sect. A Accel. Spectrom. Detect. Assoc. Equip.

    (2006)
  • A. Karabulut et al.

    Temperature-dependent electrical characteristics of Alq3/p-Si heterojunction

    Phys. B Condens. Matter

    (2018)
  • R.T. Tung

    Recent advances in Schottky barrier concepts

    Mater. Sci. Eng. R Rep.

    (2001)
  • C. Aksu Canbay et al.

    The photo-electrical performance of the novel CuAlMnFe shape memory alloy film in the diode application

    Mater. Sci. Eng., B

    (2021)
  • M.A. Manthrammel et al.

    Novel design and microelectronic analysis of highly stable Au/Indigo/n-Si photodiode for optoelectronic applications

    Solid State Sci.

    (2019)
  • F. Yakuphanoglu

    Transparent metal oxide films based sensors for solar tracking applications

    Compos. B Eng.

    (2016)
  • F. Yakuphanoglu et al.

    A hybrid p-Si/poly(1,4-diaminoanthraquinone) photoconductive diode for optical sensor applications

    Synth. Met.

    (2009)
  • R.K. Gupta et al.

    Photoconductive Schottky diode based on Al/p-Si/SnS2/Ag for optical sensor applications

    Sol. Energy

    (2012)
  • Y.S. Ocak et al.

    Temperature dependent electrical characteristics of an organic–inorganic heterojunction obtained from a novel organometal Mn complex

    Phys. B Condens. Matter

    (2010)
  • F.A. Padovani et al.

    Field and thermionic-field emission in Schottky barriers

    Solid State Electron.

    (1966)
  • S. Zeyrek et al.

    Current transport mechanism in Al/Si3N4/p-Si (MIS) Schottky barrier diodes at low temperatures

    Appl. Surf. Sci.

    (2006)
  • A. Karabulut et al.

    A novel device fabricated with Cu2NiSnS4 chalcogenide: morphological and temperature-dependent electrical characterizations

    Curr. Appl. Phys.

    (2020)
  • H. Tecimer et al.

    On the frequency and voltage dependence of admittance characteristics of Al/PTCDA/P-Si (MPS) type Schottky barrier diodes (SBDs)

    Compos. B Eng.

    (2014)
  • R. Castagne et al.

    Description of the SiO2-Si interface properties by means of very low frequency MOS capacitance Measurements

    Surf. Sci.

    (1971)
  • Ö. Sevgili et al.

    Frequency and voltage dependence of electrical and dielectric properties in metal-interfacial layer-semiconductor (MIS) type structures

    Phys. B Condens. Matter

    (2020)
  • M.O. Erdal et al.

    The rate of Cu doped TiO2 interlayer effects on the electrical characteristics of Al/Cu:TiO2/n-Si (MOS) capacitors depend on frequency and voltage

    Microelectron. Reliab.

    (2020)
  • M. Siva Pratap Reddy et al.

    Frequency dependent series resistance and interface states in Au/bio-organic/n-GaN Schottky structures based on DNA biopolymer

    Synth. Met.

    (2013)
  • M. Sharma et al.

    Frequency and voltage dependence of admittance characteristics of Al/Al2O3/PVA:n-ZnSe Schottky barrier diodes

    Mater. Sci. Semicond. Process.

    (2016)
  • Ç.G. Türk et al.

    Frequency and voltage dependence of barrier height, surface states, and series resistance in Al/Al2O3/p-Si structures in wide range frequency and voltage

    Phys. B Condens. Matter

    (2020)
  • M. Terlemezoglu et al.

    CZTS Se thin films fabricated by single step deposition for superstrate solar cell applications

    J. Mater. Sci. Mater. Electron.

    (2019)
  • H.G. Çetinkaya et al.

    Electrical characteristics of Au/n-Si (MS) Schottky Diodes (SDs) with and without different rates (graphene+Ca1.9Pr0.1Co4Ox-doped poly(vinyl alcohol)) interfacial layer

    J. Mater. Sci. Mater. Electron.

    (2017)
  • Ş. Altındal et al.

    A comparison of electrical parameters of Au/n-Si and Au/(CoSO4–PVP)/n-Si structures (SBDs) to determine the effect of (CoSO4–PVP) organic interlayer at room temperature

    J. Mater. Sci. Mater. Electron.

    (2019)
  • Z. Li et al.

    Tuning Schottky barrier height in metal/N-type germanium by inserting an ultrathin yttrium oxide film

    ECS Solid State Letters

    (2012)
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