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Papers by Murat Yıldız

Physica Scripta, 2023

Sensing in the near-infrared and visible wavelengths is critically essential for a broad range of... more Sensing in the near-infrared and visible wavelengths is critically essential for a broad range of potential applications. Colloidal quantum dot(CQD) based photodetectors provide key advantages, such as spectral tuneability, straight integration with electronic parts, high sensitivity and low cost. Here, a Schottky photodiode architecture based on CuInSe 2 (CISe) CQDs structure was designed and its photoresponse characteristics were simulated at various absorber layer thicknesses, at different back contact materials, varying light intensities, several defect densities, and different temperatures. A maximum responsivity of about 0.37 A W −1 was recorded from the proposed device. This work demonstrates that CISe CQDs are potential candidate materials for high-performance Schottky photodetectors operating in the near-infrared and visible electromagnetic spectrum.

Acta Physica Polonica A, 2013

Atomic lifetimes and energy levels were calculated using weakest bound potential model theory for... more Atomic lifetimes and energy levels were calculated using weakest bound potential model theory for 5s 2 ns 2 S 1/2 (n ≥ 6), 5s 2 np 2 P 0 1/2 (n ≥ 5), 5s 2 np 2 P 0 3/2 (n ≥ 5), 5s 2 nd 2 D 0 3/2 (n ≥ 5), 5s 2 nd 2 D 0 5/2 (n ≥ 5) series of the Rydberg states in neutral indium. The use of the quantum defect method and Martin's expression allowed us to supply lifetime values along by means of the series above. Some lifetimes and energy values not existing in the literature for high Rydberg states in neutral indium atom were obtained using this method. Our results nicely agree with the available experimental results and theoretical results.

Indian Journal of Physics, 2014

In this study, possible tautomeric forms and ground state conformers of a bis-heterocyclic monoaz... more In this study, possible tautomeric forms and ground state conformers of a bis-heterocyclic monoazo dye, 4-[ethyl 4 0-methyl-5 0-(phenylcarbamoyl)thiophene-3 0-carboxylate-2 0-ylazo]-3-methyl-1H-pyrazolin-5-one, have been calculated using density functional theory methods with 6-31G (d) basis set. 1 H and 13 C chemical shifts of tautomeric forms have been calculated. Calculated vibrational frequencies and chemical shifts have been compared with corresponding experimental data. Using time-dependent Hartree-Fock method, electronic absorption spectrum of title compound has been calculated and compared with experimental maximum wavelength data. Quantum Synchronous Transit2 approaches have been used for finding the optimum transition state and tautomeric forms of studied molecule. Calculations have shown that the most probable preferential form of this molecule in ground state is hydrazo-keto form. The calculations of frontier molecular orbitals and first order hyperpolarizability have also confirmed this stability.

Indian Journal of Physics, 2014

ABSTRACT Objective of present study is to compute molecular structures, vibrational frequencies a... more ABSTRACT Objective of present study is to compute molecular structures, vibrational frequencies and chemical shifts of phenazine derivatives using density functional theory and Hartree–Fock methods and to compare these results with experimental data. Intramolecular N–H⋯N interactions have been investigated for stabilization of the molecular conformations. Comparisons of theoretical and experimental data exhibit good correlation confirming the reliability of methods employed in this work. Moreover, frontier orbitals and molecular electrostatic potential have been visualized and calculations of the energy band gaps have been interpreted. According to the results of these investigations, we can say that DFT calculations are significantly stable in electronic structures, spectral, frontier orbitals and electrostatic potential analysis for both the phenazine derivatives.

Indian Journal of Physics, 2013

We have determined the radiative lifetimes of excited states in atomic boron using weakest bound ... more We have determined the radiative lifetimes of excited states in atomic boron using weakest bound electron potential model theory. For determining relevant parameters needed for calculation of lifetimes, we have employed numerical non-relativistic Hartree-Fock wave functions for expectation values of radius. The necessary energy values have been taken from experimental energy data from National Institute of Standards and Technology. The calculated lifetimes have been compared with available results.

Canadian Journal of Physics, 2014

The lifetimes of some excited levels for singly ionized nitrogen are calculated by using the weak... more The lifetimes of some excited levels for singly ionized nitrogen are calculated by using the weakest bound electron potential model theory and quantum defect orbital theory. We determined expectation values of radii using numerical nonrelativistic Hartree–Fock wave functions. The necessary energy values have been taken from NIST. The present results have been compared with previous calculations and experiments. Most of the lifetime results are presented for the first time in the present work. For N II, because there are few lifetime results available in the literature, the present study compared to existing investigations, provides detailed results for the lifetimes of several of the excited 2s22pns, 2s22pnp, and 2s22pd → 2s22p2 where, n = 3–6 for the ns series, n = 3–5 for the nd series and n = 3–4 for the np series.

Atomic Data and Nuclear Data Tables, 2014

Books by Murat Yıldız

FEN BILIMLERI VE MATEMATIKTE ULUSLARARASI TEORI, ARAŞTIRMA VE DERLEMELER, 2023

Fizik gibi bir bilimin felsefe ile anılması şaşırtıcı gelebilir. Oysa dış dünyanın zaman, enerji,... more Fizik gibi bir bilimin felsefe ile anılması şaşırtıcı gelebilir. Oysa dış dünyanın zaman, enerji, hareket, sonsuz ve benzeri temel kavramlara, ilk dayanak noktası doğa felsefesi ile başlamıştır. Felsefe bu noktada bazı kavramların taslağını oluşturmaktadır. Madde, doğa felsefesinde yer işgal etmesi, hareketi, hareketin ölçüsü, sonsuzluğu gibi birçok bakımdan araştırılmış ve yorumlanmıştır. Herbir filozof kendinden önceki filozoflardan kimi zaman etkilenmiş, kimi zaman onların fikirlerine katılmayarak yeni düşünceler ortaya koymuşlardır. Bu filozoflardan bazıları bu noktada zirve olmuşlardır. Bunlardan biri de Aristoteles’tir.Aristoteles, kendinden önceki felsefi sistemleri eleştirip geliştirmiş, yorumlarını sistemleştirerek bu noktada bir çığır açmıştır. İnsanoğlunun, var olanlara ilişkin sorgulaması, hayatı boyunca devam ede gelen bir süreçtir. İşte felsefe var olanların doğasının açıklanmasında ve varlığın hangi alanlarla ilgili olduğunun incelenmesinde ön plana çıkan bir bilim dalıdır.

FEN BILIMLERI VE MATEMATIKTE ULUSLARARASI TEORI, ARAŞTIRMA VE DERLEMELER, 2023

Düzenli olarak ortaya çıkan ve popüler olarak dikkat çeken bir tartışma, fizik ve felsefe arasınd... more Düzenli olarak ortaya çıkan ve popüler olarak dikkat çeken bir tartışma, fizik ve felsefe arasındaki ilişkiyle ilgilidir. Günümüz insanı bu başlık ve giriş cümlesinin felsefe ve fiziğin niçin birlikte kullandığını sorgulayabilir, yadırgayabilir. Bu düşünce fizik biliminin ilerlemesi, fiziğin dünyamızdaki belirleyiciliği, teknolojik aletlerdeki yeri düşünüldüğü zaman doğru sayılabilir veya felsefe denildiği zaman sadece metafizik algılar, fikirler, meşhur felsefeciler, kaygı veren ve anlaşılmayan derin düşünceler akla gelebilir buda bir dereceye kadar doğrudur denilebilir ama daha bilişsel olaya bakıldığı zaman durumun farklı olduğu görülecektir.Oysa dış dünyanın zaman, enerji, hareket, sonsuz ve benzeri temel kavramlara, ilk dayanak noktası doğa felsefesi ile başlamıştır. Felsefe bu noktada bazı kavramların taslağını oluşturmaktadır. Doğa felsefesinde maddenin; yer işgal etmesi, hareketi, hareketin ölçüsü, zamana bağımlılığı, sonsuzluğu birçok bakımdan araştırılmış ve yorumlanmıştır.

Physica Scripta, 2023

Sensing in the near-infrared and visible wavelengths is critically essential for a broad range of... more Sensing in the near-infrared and visible wavelengths is critically essential for a broad range of potential applications. Colloidal quantum dot(CQD) based photodetectors provide key advantages, such as spectral tuneability, straight integration with electronic parts, high sensitivity and low cost. Here, a Schottky photodiode architecture based on CuInSe 2 (CISe) CQDs structure was designed and its photoresponse characteristics were simulated at various absorber layer thicknesses, at different back contact materials, varying light intensities, several defect densities, and different temperatures. A maximum responsivity of about 0.37 A W −1 was recorded from the proposed device. This work demonstrates that CISe CQDs are potential candidate materials for high-performance Schottky photodetectors operating in the near-infrared and visible electromagnetic spectrum.

Acta Physica Polonica A, 2013

Atomic lifetimes and energy levels were calculated using weakest bound potential model theory for... more Atomic lifetimes and energy levels were calculated using weakest bound potential model theory for 5s 2 ns 2 S 1/2 (n ≥ 6), 5s 2 np 2 P 0 1/2 (n ≥ 5), 5s 2 np 2 P 0 3/2 (n ≥ 5), 5s 2 nd 2 D 0 3/2 (n ≥ 5), 5s 2 nd 2 D 0 5/2 (n ≥ 5) series of the Rydberg states in neutral indium. The use of the quantum defect method and Martin's expression allowed us to supply lifetime values along by means of the series above. Some lifetimes and energy values not existing in the literature for high Rydberg states in neutral indium atom were obtained using this method. Our results nicely agree with the available experimental results and theoretical results.

Indian Journal of Physics, 2014

In this study, possible tautomeric forms and ground state conformers of a bis-heterocyclic monoaz... more In this study, possible tautomeric forms and ground state conformers of a bis-heterocyclic monoazo dye, 4-[ethyl 4 0-methyl-5 0-(phenylcarbamoyl)thiophene-3 0-carboxylate-2 0-ylazo]-3-methyl-1H-pyrazolin-5-one, have been calculated using density functional theory methods with 6-31G (d) basis set. 1 H and 13 C chemical shifts of tautomeric forms have been calculated. Calculated vibrational frequencies and chemical shifts have been compared with corresponding experimental data. Using time-dependent Hartree-Fock method, electronic absorption spectrum of title compound has been calculated and compared with experimental maximum wavelength data. Quantum Synchronous Transit2 approaches have been used for finding the optimum transition state and tautomeric forms of studied molecule. Calculations have shown that the most probable preferential form of this molecule in ground state is hydrazo-keto form. The calculations of frontier molecular orbitals and first order hyperpolarizability have also confirmed this stability.

Indian Journal of Physics, 2014

ABSTRACT Objective of present study is to compute molecular structures, vibrational frequencies a... more ABSTRACT Objective of present study is to compute molecular structures, vibrational frequencies and chemical shifts of phenazine derivatives using density functional theory and Hartree–Fock methods and to compare these results with experimental data. Intramolecular N–H⋯N interactions have been investigated for stabilization of the molecular conformations. Comparisons of theoretical and experimental data exhibit good correlation confirming the reliability of methods employed in this work. Moreover, frontier orbitals and molecular electrostatic potential have been visualized and calculations of the energy band gaps have been interpreted. According to the results of these investigations, we can say that DFT calculations are significantly stable in electronic structures, spectral, frontier orbitals and electrostatic potential analysis for both the phenazine derivatives.

Indian Journal of Physics, 2013

We have determined the radiative lifetimes of excited states in atomic boron using weakest bound ... more We have determined the radiative lifetimes of excited states in atomic boron using weakest bound electron potential model theory. For determining relevant parameters needed for calculation of lifetimes, we have employed numerical non-relativistic Hartree-Fock wave functions for expectation values of radius. The necessary energy values have been taken from experimental energy data from National Institute of Standards and Technology. The calculated lifetimes have been compared with available results.

Canadian Journal of Physics, 2014

The lifetimes of some excited levels for singly ionized nitrogen are calculated by using the weak... more The lifetimes of some excited levels for singly ionized nitrogen are calculated by using the weakest bound electron potential model theory and quantum defect orbital theory. We determined expectation values of radii using numerical nonrelativistic Hartree–Fock wave functions. The necessary energy values have been taken from NIST. The present results have been compared with previous calculations and experiments. Most of the lifetime results are presented for the first time in the present work. For N II, because there are few lifetime results available in the literature, the present study compared to existing investigations, provides detailed results for the lifetimes of several of the excited 2s22pns, 2s22pnp, and 2s22pd → 2s22p2 where, n = 3–6 for the ns series, n = 3–5 for the nd series and n = 3–4 for the np series.

Atomic Data and Nuclear Data Tables, 2014

FEN BILIMLERI VE MATEMATIKTE ULUSLARARASI TEORI, ARAŞTIRMA VE DERLEMELER, 2023

Fizik gibi bir bilimin felsefe ile anılması şaşırtıcı gelebilir. Oysa dış dünyanın zaman, enerji,... more Fizik gibi bir bilimin felsefe ile anılması şaşırtıcı gelebilir. Oysa dış dünyanın zaman, enerji, hareket, sonsuz ve benzeri temel kavramlara, ilk dayanak noktası doğa felsefesi ile başlamıştır. Felsefe bu noktada bazı kavramların taslağını oluşturmaktadır. Madde, doğa felsefesinde yer işgal etmesi, hareketi, hareketin ölçüsü, sonsuzluğu gibi birçok bakımdan araştırılmış ve yorumlanmıştır. Herbir filozof kendinden önceki filozoflardan kimi zaman etkilenmiş, kimi zaman onların fikirlerine katılmayarak yeni düşünceler ortaya koymuşlardır. Bu filozoflardan bazıları bu noktada zirve olmuşlardır. Bunlardan biri de Aristoteles’tir.Aristoteles, kendinden önceki felsefi sistemleri eleştirip geliştirmiş, yorumlarını sistemleştirerek bu noktada bir çığır açmıştır. İnsanoğlunun, var olanlara ilişkin sorgulaması, hayatı boyunca devam ede gelen bir süreçtir. İşte felsefe var olanların doğasının açıklanmasında ve varlığın hangi alanlarla ilgili olduğunun incelenmesinde ön plana çıkan bir bilim dalıdır.

FEN BILIMLERI VE MATEMATIKTE ULUSLARARASI TEORI, ARAŞTIRMA VE DERLEMELER, 2023

Düzenli olarak ortaya çıkan ve popüler olarak dikkat çeken bir tartışma, fizik ve felsefe arasınd... more Düzenli olarak ortaya çıkan ve popüler olarak dikkat çeken bir tartışma, fizik ve felsefe arasındaki ilişkiyle ilgilidir. Günümüz insanı bu başlık ve giriş cümlesinin felsefe ve fiziğin niçin birlikte kullandığını sorgulayabilir, yadırgayabilir. Bu düşünce fizik biliminin ilerlemesi, fiziğin dünyamızdaki belirleyiciliği, teknolojik aletlerdeki yeri düşünüldüğü zaman doğru sayılabilir veya felsefe denildiği zaman sadece metafizik algılar, fikirler, meşhur felsefeciler, kaygı veren ve anlaşılmayan derin düşünceler akla gelebilir buda bir dereceye kadar doğrudur denilebilir ama daha bilişsel olaya bakıldığı zaman durumun farklı olduğu görülecektir.Oysa dış dünyanın zaman, enerji, hareket, sonsuz ve benzeri temel kavramlara, ilk dayanak noktası doğa felsefesi ile başlamıştır. Felsefe bu noktada bazı kavramların taslağını oluşturmaktadır. Doğa felsefesinde maddenin; yer işgal etmesi, hareketi, hareketin ölçüsü, zamana bağımlılığı, sonsuzluğu birçok bakımdan araştırılmış ve yorumlanmıştır.