Karaduman, Oktay; Canbay, Canan Aksu; Dere, Aysegul; Orman, Yusuf; Al-Ghamdi, Ahmed A; Al-Sehemi, Abdullah G; Yakuphanoglu, Fahrettin

In this work, a novel smart (shape memory) alloy metalized photonic silicon wafer photodiode with Schottky type CuAlV/n-Si/Al contact structure as a nano-electro-mechanical-system (NEMS) photodevice was fabricated by thermal evaporation technique. The CuAlV memory alloy used as the top Schottky metal contact electrode was produced by arc melting technique and a subsequent quenching in an iced-brine water medium, and its shape memory effect characteristics were revealed by thermal and structural tests. The fabricated photonic NEMS photodiode was characterized by different photo-electrical (I-V, I-t) and frequency/time dependent and illuminated capacitance (C-V/f, C-t, C-V/ill.) and conductance-voltage (G-V) measurements under different frequencies and artificial light intensity power conditions. The I-V tests showed an excellent current rectifying ability and very well net photocurrent generation features of the photodiode. The specific detectivity of the photodiode was found as high as almost approaching 1011 Jones. The SCLC (space charge limited current conduction) analyses made on the double-log I-V plots of the photodiode revealed that the trap-filling TFL-SCLC and trap-free SCLC current conduction mechanisms are the two prevailing conduction mechanisms in the forward bias voltage region. The density of interface states (Dit) of the fabricated photodiode was determined. Moreover, an excellent reproducibility of light-induced photocapacitance formation of the novel photodiode was demonstrated by C-V/t measurements under different artificial light power intensities.

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Aydin, Cihat; Aydin, Handan; Yakuphanoglu, Fahrettin

In this study, X-ray diffraction, electrical conductivity, optical and dielectrical properties of the InTe amorphous semiconductor material have been investigated. X-ray diffraction results show that InTe sample has an amorphous structure. Temperature dependence of electrical conductivity of the sample has been investigated and the obtained results confirm that InTe is an amorphous semiconductor. The InTe sample shows photoconductivity behavior. The optical band gap and optical constants of the sample were calculated using transmittance and reflectance spectra. In the sample, the direct optical transitions take place The refractive index dispersion curve of the sample obeys the single oscillator model. The dielectrical properties of the sample have been investigated as a function of frequency and temperature. It was found that the dielectrical parameters were changed with temperature and frequency. The electrical modulus curves were used to analyze the dielectrical relaxation processes.

İncele

Aydin, Cihat; Aydin, Handan; Taskin, Mustafa; Yakuphanoglu, Fahrettin

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Aydın, Handan; Yakuphanoglu, Fahrettin; Aydın, Cihat

In this study, zinc oxide thin films doped with Al at different atomic ratios (0.1%, 0.5%, 1%, 2%, 5%) were prepared using sol-gel spin coating method. Crystal structure, surface morphology, optical properties of the films and their response to ammonia gas were examined. XRD results showed that the ZnO thin films had a hexagonal polycrystalline structure. It was concluded from the calculation of the crystal size and lattice constant of the films that the produced samples were a nanomaterial. Scanning electron microscope (SEM) and atomic force microscope (AFM) images of the samples revealed that the morphology was composed of nanostructured particles and a cluster structure made of the combination of these particles. The optical band gap (Eg) of the prepared films were found within the range of 3.251 eV–3.342 eV by using the optical absorption method. Characteristics of susceptibility against ammonia gas were evaluated depending on the Al dopant. The obtained results showed that the gas response along with the structural, morphological, and optical properties of ZnO thin films changed with Al dopant. The produced thin film samples can be used as a sensor for the detection of ammonia gas in various industrial branches.

AtıfScopus66·WoS59·OpenAlex76

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Aslan, Naim; Koç, Mümin Mehmet; Dere, Ayşegül; Arif, Bilal; Erkovan, Mustafa; Al-Sehemi, Abdullah G.; Al-Ghamdi, Ahmed A.; Yakuphanoglu, Fahrettin

Electrochemical deposition technique was used to fabricate titanium doped amorphous carbon (Ti doped a:C) Al/Ti-a:C/p-Si/Al photodiode. The effects of illumination on the current–voltage (I–V) characteristics of the Al/a:C/p-Si/Al doped Ti diode for optoelectronic applications were investigated. The reverse current of the diode increased with the increasing illumination intensities when the bias voltage was applied. By using the forward bias I–V characteristics, the ideality factor (n) and barrier height (Φb) of Al/Ti-a:C/p-Si photodiode structure was found as 1,84 and 0,50 eV, respectively. In addition, the capacitance–voltage (C–V) and conductance–voltage (G–V) measurements of the diode were studied in the frequency range of 100 kHz–600 kHz. The measured values of the capacitance decreased with the increasing frequency. The photoelectrical properties of Al/Ti-a:C/p-Si/Al device indicates that the photodiode investigated in this paper has great potential to be used in optoelectronic device applications and in industry.

AtıfScopus41·OpenAlex43

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