Conductance and Density of Interface State Characteristics of Mn Doped CdO Photodiodes

Sol-gel technique was used to fabricate CdO and Mn doped CdO solutions which were used to produce thin films. Undoped and 0.2% Mn doped, 6% Mn doped, and 10% Mn doped solutions were spin coated on Si wafers to fabricate photodiodes. Conductance – voltage (G - V) measurements were performed. Mn doping enhances the conductance properties of the CdO diodes. Increased conductance characteristics were obtained with increasing AC signal frequency. Corrective conductance – voltage (Gadj – V) graphs were obtained using conductance voltage graphs. Increased corrective conductance (Gadj) values were obtained with increasing AC signal frequency. Using corrective conductance – voltage (Gadj – V) and conductance – voltage (G - V) data density of interface states (Dit) values of the diodes were calculated. Different density of state values were obtained for the different photodiode. Density of state values were found to increase with increased Mn doping

Size investigation of silicon nanoclusters deposited on HOPG using noncontact atomic force microscopy

The sizes of silicon nanoparticles produced using two different novel methods are investigated in this report. The method of production used to generate silicon oxide nanoparticles was achieved via gas aggregation codeposition with water on a cold target, and also via a liquid jet method. The nanoparticles were drop-cast on a highly oriented pyrolytic graphite (HOPG) substrate and assessed using ultrahigh vacuum atomic force microscopy (AFM). Noncontact constant force mode was used in the AFM investigations. The silicon nanoparticles produced using the gas aggregation and water codeposition method were found to be smaller than 2 nm. A degree of deviation in the measured sizes of the silicon nanoparticles in different layers was detected. The size deviation was attributed to surface-nanoparticle, surface-tip, and nanoparticle-tip interactions. Silicon nanoparticles produced in alcohol using the liquid jet method were also found to be smaller than 2 nm. The solvent used for the silicon nanoparticles was varied in our investigations. When water was used as a solvent, a size deviation for silicon nanoparticles in different layers was also observed.Kirklareli University Scientific Research Project office (KLUBAP) [KLUBAP - 115]I am thankful to the Kirklareli University Scientific Research Project office (KLUBAP) for support and partial funding (project number KLUBAP - 115). I also would like to thank Dr Klaus von Haeften, Dr Hanieh Yazdanfar, and Dr Michael McNally for their support.WOS:0004415950000122-s2.0-8505155196

Photoelectrical properties of solar sensitive CuO doped carbon photodiodes

The CuO doped carbon thin films were produced by using electrochemical deposition and the surface characteristics of the photodiodes were investigated using the scanning electron microscopy and infrared (IR) spectroscopy. Illumination behaviours and current - voltage (I-V) characteristics were assessed. Diodes show rectifying characteristics, where reverse current at backward bias region showed increasing characteristics with increasing illumination intensities. I-V characteristics curves were used to calculate the ideality factor (n) and barrier height (Phi(B)); the average ideality factor and barrier height were found as 3.74 and 0.51 eV, respectively. Moreover, capacitance - voltage (C-V) and conductance - voltage (G - V) curves were assessed. Capacitance values showed a decreasing trend with increasing frequency. C-adj and G(adj) characteristics were evaluated and the density of interface states (D-it) and series resistance (R-s) were calculated using C-V and G -V curves. Detailed investigation of CuO doped amorphous carbon photodiodes (CuO-a:C) revealed that photodiodes exhibited quite good solar sensitive and photo-responsive properties. Overall performance of the photodiodes indicates that CuO-a:C diodes have great potential to be used as a photodetector in optoelectronic devices and their applications. (C) 2020 Elsevier B.V. All rights reserved.WOS:0005191895000292-s2.0-8507931904

Optimization of KI as X-Ray Computed Microtomography Contrast Agents for Murine and Chicken Epidermal Tissues Applications

X-ray computed tomography (CT) is vastly used in many different applications in different fields such asmaterials science, medical science, entomology, anatomy, marine sciences. Since the X-ray is highly penetrable,3D image of almost any material can be achieved by CT. The high quality image of the materials, which arecomposed of different types of atoms, can easily be achieved. However, obtaining the high quality images of thematerials which has similar types of atoms or relatively soft structure becomes problem. Scientist investigatingthe soft tissues such as flesh, muscle, cartilage or animals in soft structure suffer from this problem. At this point,staining procedure, treating materials with contrast agents help researcher to enhance the image quality. In thiswork, optimization of KI based staining to obtain enhanced image quality in CT imaging of murine and chickendermal tissues were studied. Results indicate that overstaining or staining the tissues in less concentrationsignificantly affects the quality of the obtained CT images

Optimization of KI as X-Ray Computed Microtomography Contrast Agents for Murine and Chicken Epidermal Tissues Applications

X-ray computed tomography (CT) is vastly used in many different applications in different fields such asmaterials science, medical science, entomology, anatomy, marine sciences. Since the X-ray is highly penetrable,3D image of almost any material can be achieved by CT. The high quality image of the materials, which arecomposed of different types of atoms, can easily be achieved. However, obtaining the high quality images of thematerials which has similar types of atoms or relatively soft structure becomes problem. Scientist investigatingthe soft tissues such as flesh, muscle, cartilage or animals in soft structure suffer from this problem. At this point,staining procedure, treating materials with contrast agents help researcher to enhance the image quality. In thiswork, optimization of KI based staining to obtain enhanced image quality in CT imaging of murine and chickendermal tissues were studied. Results indicate that overstaining or staining the tissues in less concentrationsignificantly affects the quality of the obtained CT images

A GLIMPS TO THE MODERN OPTICIANRY TECHNIQUES

DergiPark: 951990klujesMillions of people are suffering from eye refractive errors such as myopia, hypermetropia, astigmatism, presbyopia, etc. Every day, modern opticianry techniques were used to diagnose and treat the patients. And they find solutions to such disorders; therefore, touching the lives of millions of people. In the last decades, laser surgery becomes popular. However, it still has the risk to damage the inner structure of eyeballs such as the inner lens, cornea, etc. Laser surgery is costly since it requires high tech equipment and good experience with outstanding surgical skills. At this point, people continue their daily life via their glasses or contact lenses where simple and effective techniques can solve the problem of millions of people who suffer from refractive errors. In this report, we briefly explain the eye refractive errors and lenses used in the treatment of such errors. We discuss lens types and properties, lens prescriptions, lens cut and preparation techniques, frame types, and contact lenses.Milyonlarca insan miyopi, hipermetropi, astigmatizm gibi göz kusurlarından muzdariptir. Her gün modern optisyenlik teknikleri kullanılarak milyonlarca insanın muzdarip olduğu bu göz kusurları teşhis ve tedavi edilmektedir. Son yıllarda lazer cerrahisi gibi teknikler göz kusurlarının tedavisinde yaygın olarak kullanılmaktadır. Ancak bahsi geçen tekniklerin göz küresinin içerisinde bulunan kornea, mercek aköz hümor gibi hassas yapılara uygulanması oldukça risklidir. Lazer cerrahisi operasyonlarında yüksek teknoloji içeren ve sınırlı sayıda üretilmiş cihazlar kullanıldığı için bu uygulamalar oldukça pahalıdır. Ayrıca bu operasyonların başarılı bir şekilde uygulanabilmesi için yüksek tecrübeli ve iyi yetişmiş hekimlere ihtiyaç duyulmaktadır. Bu sebepten insanların çoğu günlük hayatına gözlük ya da kontakt lensler ile devam etmektedirler ki bu aparatlar basit ve etkili bir şekilde insanların göz kusurlarından doğan sorunları ortadan kaldırmaktadır. Raporumuzda kısaca göz kusurlarını açıklayıp göz kusurları tedavisinde kullanılan lensler tartışılacaktır. Ayrıca cam (lens / mercek) tipleri ve özellikleri, gözlük camı reçeteleri, gözlük camı (lensi) kesim ve hazırlama teknikleri, çerçeve tipleri ve mercekler ile ilgili genel teknik bilgiler verilecektir

Mn Katkılı CdO Fotodiyotların İletkenlik ve Arayüz Durum Yoğunluğu Karakteristikleri

Sol-gel technique was used to fabricate cadmium oxide and manganese doped cadmium oxide solutions whichwere used to produce thin films. 10% manganese doped, %6 manganese doped, %0.2 manganese doped andundoped cadmium oxide solutions were spin-coated on Si wafers to fabricate photodiodes. Conductance –voltage (G - V) measurements were performed. Mn doping enhances the conductance properties of the CdOdiodes. Increased conductance characteristics were obtained with increasing AC signal frequency. Correctiveconductance – voltage (Gadj – V) graphs were obtained using conductance voltage graphs. Increased correctiveconductance (Gadj) values were obtained with increasing AC signal frequency. Using corrective conductance –voltage (Gadj – V) and conductance – voltage (G - V) data density of interface states (Dit) characteristics of thediodes were assessed. Different density of state values was obtained for the different photodiodes. The densityof state values was found to increase with increased Mn doping.İnce film üretiminde kullanılan CdO ve Mn katkılı CdO çözeltiler Sol-gel yöntemi kullanılarak üretildi. Katkısız, %0.2 Mn katkılı, %6 Mn katkılı ve %10 Mn katkılı CdO çözeltileri spin kaplama yöntemi kullanılarak silisyum tabakalar üzerine fotofiyot üretim amacı ile kaplandı. İletkenlik – voltaj (G - V) ölçümleri gerçekleştirildi. Mn katkılamanın CdO fotodiyotların iletkenlik özelliklerini iyileştirdiği görüldü. Artan AC sinyal frekansı ile iletkenlik karakteristiğinin de artış gösterdiği tespit edildi. Düzeltilmiş iletkenlik – voltaj (Gadj – V) grafikleri, iletkenlik – voltaj grafikleri kullanılarak elde edildi. Artan AC sinyal frekansı ile düzeltilmiş iletkenlik değerinin de artış gösterdiği anlaşıldı. Düzeltilmiş iletkenlik – voltaj ve iletkenlik – voltaj grafikleri kullanılarak arayüz durum yoğunluğu değerleri elde edildi. Üretilen farklı fotodiyotlar için farklı arayüz durum yoğunluğu değerleri var olduğu anlaşıldı. Arayüz durum yoğunluğu değerlerinin Mn katkılaması ile arttığı keşfedildi

Wet-chemical etching of GaAs(211)B wafers for controlling the surface properties

Substrate surface plays an important role to achieve high performance infrared devices and high-quality film layers. GaAs (211)B wafers were intensively used in infrared detector applications. Despite 'epiready' wafers can easily be found on the market, most of them have defects and contaminations due to their fabrication processes. The defects and contaminations on wafers may have deleterious effects on thin film growth and detector applications. To overcome such problems, various chemical treatments should be implemented prior to thin film growth. In this study, to understand the effect of wet chemical cleaning process on epiready (211)B GaAs wafers, piranha solution-based wet chemical etching was performed. After these treatments, the surfaces of GaAs wafers were investigated by atomic force microscopy and scanning electron microscopy. Energy dispersive X-ray spectroscopy was used to assess the chemical composition of the surface. The vibrational modes and two-dimensional maps were observed by a Raman spectroscopy.WOS:0005118797000012-s2.0-8507271148

INFRARED DETECTING BEHAVIOURS OF Cu2NiSnS4 PHOTODIODES

DergiPark: 702575klujesA photodetector in Al/p-Si/Cu2NiSnS4/Al form was produced using sol-gel method. Scanning electron microscopy (SEM) was used in the structural assessment of the photodetectors. Microscopic investigations showed that Cu2NiSnS4 structures were formed in nanostructure in granular form. Current–time and current-voltage investigations confirmed that Al/p-Si/Cu2NiSnS4/Al photodiodes have infrared sensing properties. Photodetection properties such as linear dynamic rate, ideality factor, photosensitivity, and photoresponse characteristics were assessed. Results also validate the infrared sensing properties of the diodes. The barrier height of the Al/p-Si/Cu2CoSnS4/Al diodes was calculated as 0.466 eV. Ideality factor of the diodes was found to be 5.16. Results indicate that our Al/p-Si/Cu2CoSnS4/Al diodes are suitable for infrared tracking device applications.Al/p-Si/Cu2NiSnS4/Al yapıdaki fotodedektörler sol-jel yöntemi kullanılarak üretilmiştir. Taramalı elektron mikroskobu (SEM) kullanılarak fotodedektörler yapısal olarak incelenmiştir. Mikroskopik incelemeler sonucunda Cu2NiSnS4 yapının nanoformda sentezlendiği ve nanoparçacıkların granüler yapıda bir arada bulunduğu gözlemlenmiştir. Akım – zaman ve akım - voltaj gafikleri Al/p-Si/Cu2NiSnS4/Al yapıda üretilmiş olan diyotlarımızın kızılötesini ışığı hisedebilme özellikleri gösterdiğini göstermiştir. Fotodedektör özelliklerini incelemede kullanılan lineer dinamik oran, idalite faktörü, fotohassasiyet, fototepki karasteriklikleri gibi karaktersistik özellikler çalışmamızda detaylıca incelenmiştir. İncelenen fotodiyot karakteristikleri de fotodiyotlarımızın kızılötesi dedektör özellikleri gösterdiğini doğrulamıştır. Al/p-Si/Cu2NiSnS4/Al yapıdaki diyotlarımıza ait bariyer yüksekliği 0.466 eV olarak hesaplanırken idealite faktörü ise 5.16 olarak bulunmuştur. Sonuçlar incelendiğinde Al/p-Si/Cu2NiSnS4/Al yapıda üretilmiş fotodiyotların infrared tarama cihazlarında kullanılmaya uygun olduğu anlaşılmaktadır

Spectroscopic and microscopic investigation of MBE-grown CdTe (211) B epitaxial thin films on GaAs (211)B substrates

CdTe epitaxial thin films, for use as a buffer layer for HgCdTe defectors, were grown on GaAs (211)B using the molecular beam epitaxy method. Wet chemical etching (Everson method) was applied to the epitaxial films using various concentrations and application times to quantify the crystal quality and dislocation density. Surface characterization of the epitaxial films was achieved using Atomic force microscopy and Scanning electron microscopy (SEM) before and after each treatment. The Energy Dispersive X-Ray apparatus of SEM was used to characterize the chemical composition. Untreated CdTe films show smooth surface characteristics with root mean square (RMS) roughnesses of 1.18-3.89 nm. The thicknesses of the CdTe layers formed were calculated via FTIR spectrometry and obtained by ex situ spectroscopic ellipsometry. Raman spectra were obtained for various temperatures. Etch pit densities (EPD) were measured, from which it could be seen that EPD changes between 1.7 x 10(8) and 9.2 x 10(8) cm(-2) depending on the concentration of the Everson etch solution and treatment time. Structure, shape and depth of pits resulting from each etch pit implementation were also evaluated. Pit widths varying between 0.15 and 0.71 mu m with heights varying between 2 and 80 nm were observed. RMS roughness was found to vary by anything from 1.56 to 26 nm.Gediz Project at Izmir Institute of TechnologyIzmir Institute of TechnologyThis study was supported by the Gediz Project at Izmir Institute of Technology. The authors would like to thank all supporters for their assistance with the project. This paper is dedicated to the memory of Prof Yusuf Selamet, who sadly passed away in 2016. We are grateful to him for his guidance, endless support and giving us the chance to work with him. In addition, we would like to thank Elif Bilgilisoy for helping in etching CdTe epitaxial films and also Merve Karakaya for Spectroscopic Ellipsometry analysis. Use of facilities at the IZTECH Material Research Center for scanning electron microscopy is acknowledged.WOS:0004426683000312-s2.0-8506034124