A comparative study on the electrical characterization of Al/p-Si (MS) structures with and without interfacial perylene (C2OH12) layer at room temperature

Bu çalışmada, Al/p-Si Schottky engel diyotun (D1) performansını artırmak amacıyla Al ile p-Si arasına ince bir perylene (C20H12) tabakası spin coating yöntemi ile büyütülerek Al/C20H12/p-Si tipi Schottky engel diyotu (D2) hazırlandı. Hazırlanan bu iki tip diyotun idealite faktörü (n), engel yüksekliği (?Bo ), seri direnç (Rs), kısa devre direnci (Rsh), ara yüzey durumları (Nss) ve tüketim tabasının genişliği (WD) gibi temel elektriksel parametreleri oda sıcaklığında elde edildi ve karşılaştırıldı. Bu karşılaştırma, doğru ve ters öngerilim altında, 1 MHz de, akım-voltaj (I-V), kapasitans-voltaj (C-V) ve kondüktans- voltaj (G/w) ölçümleri kullanılarak yapıldı. Elde edilen deneysel sonuçlar, tüm bu parametrelerin hem frekansa hem de arayüzey tabakasına oldukça bağlı olduğunu gösterdi. Al/p-Si diyotlarda doğrultma oranı (±3V da) 2,1x103 iken, Al/C20H12/p-Si diyotlarda ise 1,7x104 olarak bulundu. Aynı zamanda Al/C20H12/p-Si diyotunda kaçak akımının büyüklüğünün, Al/p-Si Schottky diyota göre 10 kat daha düşük olduğu görüldü. Benzer şekilde Ohm Yasası kullanılarak elde edilen Rs ve Rsh değerleri sırasıyla, doğru öngerilim ve ters öngerilim eğrilerinden, Al/C20H12/p-Si Schottky engel diyotu için 544?? ve 11M??, Al/p-Si Schottky engel diyotu için 716 ? ve 1,83 M? olarak bulundu. Bunlara ilave olarak Al/C20H12/p-Si ve Al/p-Si diyotlarının voltaja bağlı Nss dağılım profili düşük-yüksek frekans-kapasitans (CLF-CHF) metodu kullanılarak elde edildi. Al/C20H12/p-Si diyotu için Nss değerlerinin, Al/p-Si diyotu değerlerinden 2 kat daha düşük olduğu görüldü. Elde edilen bu deneysel sonuçlar ışığında, kullanılan perylene (C20H12) arayüzey polimer tabakasının, Schottky diyotunun performansını oldukça iyileştirdiği görülmektedir.Perylene (C20H12) thin interfacial layer was deposited on p-Si using spin coating system to improve the performance of Al/p-Si Schottky barrier diode (SBD). In order to compare with and without perylene SBD Al/C20H12/p-Si and Al/p-Si type diodes were fabricated and they called as D2 and D1 respectively. The main electrical parameters of D1 and D2 diodes, such as ideality factor (n), barrier height (?B), series resistance (Rs), shunt resistance (Rsh), voltage dependent density distribution profile of interface states (Nss) and depletion layer width (WD) were obtained from the forward bias current-voltage (I-V) and admittance spectroscopy methods (capacitance-voltage (C-V) and conductance-voltage (G/w-V) measurements) at room temperature. Experimental results show that the rectifying ratio of Al/p-Si type SBD is 2,1x103 while with C20H12 type SBD is 1,7x104 at (± 3 V). Also, the leakage current was found very sensitive to the C20H12 and the magnitude of the leakage current of perylene based diode is almost one order lower than that of MS or D1 diode. Similarly, the values of Rs and Rsh were obtained from the forward bias I-V data using Ohm?s Law and they found as 716 ? and 1,83 M??for the MS-type SBD and 544 ? and 11 M??for the MPS-type SBD. In addition, the voltage dependent density distribution profile of Nss of the MS and MPS type SBDs were obtained by the low-high frequency capacitance (CLF-CHF) method and the obtained mean value of Nss for MPS SBD is two times lower than that for MS SBD. These results show that the performance of the MS type SBD can be improved by using with a thin interfacial C20H12 polymer layer between metal and semiconductor

The Comparıson Of Electrıcal Characterıstıcs Of Schottky Barrıer Dıodes Wıth And Wıthout Polymer Interfacıal Layer

Bu çalışmada, arayüzey tabakasının elektriksel karakteristikler üzerine etkilerinin ve pozitif voltaj C-V eğrilerindeki anormal pik ile negatif kapasitans davranışlarının kaynaklarının incelenmesi hedeflenmiştir. Bu amaçla Polypyrrole (PPy) polimer arayüzey tabakalı Cr/PPy/p-Si (MPS) ve arayüzey tabakasız Cr/p-Si (MS) Schottky engel diyotlarının (SBDs) üretimi yapılmıştır. Üretimi yapılan MS ve MPS tipi SBD'lerin 10 kHz-5 MHz frekans ve (-4V)-(+4V) voltaj aralığında kapasitans-voltaj (C-V), kondüktans-voltaj (G/-V) karakteristikleri ve aynı voltaj aralığında akım-voltaj (I-V) karakteristikleri incelenmiş ve diyotların karşılaştırılması yapılmıştır. Diyotların elektriksel karakteristiklerini önemli ölçüde etkileyen faktörlerden olan arayüzey durumlarının (Nss) dağılımı ve diyotun seri direnci (Rs), sırasıyla Hill Coleman ve Nicollian-Brews metotları kullanılarak elde edilmiştir. Elde edilen C-V eğrilerinin pozitif voltaj (yığılma) bölgesinde anormal pik gösterdiği ve daha sonra herbir frekans için negatif kapasitansa (NC) gittiği gözlemlenmiştir. C'deki azalmaya karşılık kondüktansta (G/) bir artış gözlemlenmiş ve aygıtın indüktif davranış gösterdiği belirlenmiştir. Ayrıca bu çalışmadan elde edilen deneysel sonuçlara göre MPS tipi SBD'nin C-V eğrilerinde pozitif voltaj bölgesindeki NC davranışının, PPy arayüzey tabakası nedeniyle kaybolduğu gözlemlenmiştir. MPS tipi SBD'nin daha yüksek doğrultma oranına, daha düşük kaçak akım değerine ve daha az Nss değerlerine sahip olduğu gözlemlenmiştir. Bütün bu deneysel sonuçlara göre Nss'lerin, Rs'nin ve arayüzey PPy tabakasının, diyotların I-V, C-V ve G/-V karakteristiklerinde oldukça etkin olduğu sonucuna varılmıştırIn this study, the effects of interface layer on electrical characteristics, the anomalous peak and the sources of negative capacitance behavior in positive voltage C-V curves were investigated. For this purpose, Cr/p-Si Schottky barrier diodes (SBDs) with and without Polypyrrole (PPy) polymer interfacial layer have been fabricated. Both the capacitance-voltage (C-V) and conductance-voltage (G/-V) measurements of the Cr/p-Si (MS) and Cr/PPy/p-Si (MPS) SBDs have been investigated in the applied bias voltage range of (-4V)-(+4V) as function of frequency (10 kHz-5 MHz) and they have been compared in detail. The distribution of interface states (Nss) which affects the electrical characteristics of the diodes and series resistance of the diodes (Rs) were obtained using Hill-Coleman and Nicollian and Brews methods, respectively. It is seen that the resulting C-V curves of the positive voltage (clutter) region showed anomalous peak and then for each frequency, they went to negative capacitance (NC). Compared to the reduction in C, conductance (G/) showed an increase and the device has showed inductive behavior. Experimental results also show that, in an interesting way, this negative capacitance (NC) behavior in the forward bias region disappears in the C-V plot of MPS type SBD due to the existence of PPy interlayer. As a result, MPS type SBD has a higher rectification rate with low reverse leakage current and Nss when compared with the MS type SBD. All of these experimental results confirmed that the distribution of Nss, Rs and Ppy interface layer has significantly improved the electrical characteristics of the diod

Effects of frequency and bias voltage ondielectric properties and electric modulus ofAu/Bi4Ti3O12/n-Si (MFS) capacitors

In this work, a metal-ferroelectric-semiconductor (MFS) type capacitor was fabricated and admittance measurements were held in a wide frequency range of 1 kHz-5 MHz at room temperature for the investigation of frequency and voltage dependence of complex dielectric constant, complex electric modulus and electrical conductivity of the MFS capacitor. Bismuth titanate (Bi4Ti3O12) with high dielectric constant was used as interfacial ferroelectric material and the structure of MFS capacitor was obtained as Au/Bi4Ti3O12/n-Si. Experimental results showed that dielectric, modulus and conductivity parameters are strong functions of frequency and voltage especially in depletion and accumulation regions due to the existence of surface states (Nss), series resistance (Rs), interfacial polarization and interfacial layer. It was found that Rs of the structure and interfacial ferroelectric layer are efective in accumulation region whereas surface states (Nss) and interfacial polarization are efective in depletion region. Also the changes in dielectric, modulus and conductivity parameters become considerably high particularly at low frequencies due to high values of Rs and Nss. The observed anomalous peak in voltage dependent plots of capacitance and dielectric constant was atributed to the particular density distribution of Nss, Rs and minority carrier injection. Moreover, the value of conductivity at low and intermediate frequencies is almost independent of frequency thus low frequency data was used to extract d.c. conductivity. This work showed that the use of high-dielectric Bi4Ti3O12 as ferroelectric interfacial layer in a MFS capacitor is preferable due to high values of its dielectric constant compared with traditional insulator layer materials such as SiO2 and SnO2. Therefore, a MFS capacitor with Bi4TiO12 interfacial layer can store more energy thanks to its high dielectric constant

Investigation of the efficiencies of the (SnO2-PVA) interlayer in Au/n-Si (MS) SDs on electrical characteristics at room temperature by comparison

© 2019, Springer Science+Business Media, LLC, part of Springer Nature.Au/n-Si (MS) and Au/(SnO2-PVA)/n-Si (MPS) type SDs were manufactured at identical conditions for investigation of the (SnO2-PVA) organic/polymer interlayer effects on the electrical characteristics using voltage dependent current (I) and capacitance/conductance (C/G) data and compared each other. Rectifying ratio (RR) and the barrier height (BH) were found from forward bias ln(I)–V plots,. The values found are 2.5 × 102 and 0.57 eV for MS type SDs and 2 × 103 and 0.68 eV for MPS type SDs, respectively. The ideality factor (n), series resistance (Rs) and BH were also calculated from Cheung’s functions. They are agreement observed to be compatible with other results. The surface states versus (Ec−Ess) and Rs versus V curves were calculated by using the I–V data by using Roderick and Ohm’s law. The doping donor atoms (ND), Fermi energy (EF), BH of these SDs were also calculated from the reverse bias C−2–V data. While the calculated values of surface states and leakage current for the MPS is lower than Au/n-Si SD, RR is higher. Obtained results prove the use of a (SnO2-PVA) organic interlayer improved the performance of the Au/n-Si diodes