http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Strain-controlled Flexible DNA-curcumin on PET Substrate
Siva Pratap Reddy Mallem(말렘 시바 프래탑 래디),Jung-Hee Lee(이정희) 대한기계학회 2021 대한기계학회 춘추학술대회 Vol.2021 No.4
High-performance strain-modulated flexible sensors are significant modules of the systems for human motion detection, electronic skin, human-machine interaction, soft robotics, etc., which are intended as important technologies for applications in future human personal healthcare monitoring and artificial intelligence. Resistive switching, which use modification in resistance measurement, is considered as one of the prospective candidate for the future generation key technology. We introduce a simple technique to fabricate a flexible resistive-type strain sensor composted of DNA-curcumin composite and graphene on polyethylene terephthalate (PET) substrate. Double helical DNA has unique attributes including its high thermal stability, high negative charge density and strong resistance to both bending and twisting. Particularly, flexible DNA-curcumin/graphene on PET substrate displays piezo-resistive characteristics, is likely a good candidate for fabricating resistance-based strain sensors.
Gate Architecture Effects on the Gate Leakage Characteristics of GaN Wrap‑gate Nanowire Transistors
Siva Pratap Reddy Mallem,Ki‑Sik Im,Terirama Thingujam,Jung‑Hee Lee,Raphael Caulmilone,Sorin Cristoloveanu 대한금속·재료학회 2020 ELECTRONIC MATERIALS LETTERS Vol.16 No.5
Gate leakage current in lateral GaN wrap-gate nanowire transistors (WG-NWT) was investigated using current density–voltage (Jg–Vg) characteristics at room temperature. We found that the gate leakage current is strongly dependent on thetop corner angle of the gate architecture. This leakage current was characterized by considering hopping (Poole–Frenkelemission) and trap-assisted thermionic emission mechanisms. Despite its smaller gate area, the gate leakage current of thelateral GaN WG-NWT without a 2DEG channel was higher than that of the device with a 2DEG channel for all applied gatebiases. The reason for this is that the lateral GaN WG-NWT without 2DEG channel has a triangular cross-section with asharp top corner angle resulting in a strong electric field due to geometrical field enhancement.
Siva Pratap Reddy, M.,Rajagopal Reddy, V.,Jyothi, I.,Choi, Chel‐,Jong John Wiley Sons, Ltd. 2011 Surface and interface analysis Vol.43 No.9
<P><B>Abstract</B></P><P>Schottky rectifiers are fabricated on <I>n</I>‐type GaN using Ni/Pd metallization scheme and its characteristics have been investigated by current‐voltage (I‐V), Capacitance‐Voltage (C‐V), X‐Ray Diffraction (XRD) and SIMS measurements as a function of annealing temperature. The calculated Schottky barrier height of the as‐deposited contact was found to be 0.60 eV (I‐V), 0.71 eV (C‐V) with an ideality factor of 1.44. However, the barrier height slightly increases after annealing at 300, 400 and 500 °C. On the basis of the experimental results, a high‐quality Schottky contact with barrier height and ideality factor of 0.81 eV (I‐V), 0.88 eV (C‐V) and 1.13 respectively, can be obtained after annealing at 600 °C for 1 min in a nitrogen atmosphere. Further, after annealing at 700 °C, it is found that the barrier height slightly decreased to 0.74 eV (I‐V) and 0.85 eV (C‐V). From the above observations, one can note that Ni/Pd Schottky contact exhibits excellent electrical properties after a rapid thermal annealing at 600 °C. According to the SIMS and XRD analysis, the formation of gallide phases at the Ni/Pd/<I>n</I>‐GaN interface could be the reason of the barrier height increase at elevated annealing temperatures. The Atomic Force Microscopy (AFM) results show that the overall surface morphology of Ni/Pd Schottky contacts on <I>n</I>‐GaN is fairly smooth. The above observations reveal that Ni/Pd Schottky metallization scheme was a good choice for the fabrication of high‐temperature and high‐power device applications. Copyright © 2010 John Wiley & Sons, Ltd.</P>
DNA-CTMA/a-Si:H bio-hybrid photodiode: A light-sensitive photosensor
Reddy, M. Siva Pratap,Puneetha, P.T.,Lee, Young-Woong,Jeong, Seong-Hoon,Park, Chinho Elsevier 2017 Organic electronics Vol.50 No.-
<P><B>Abstract</B></P> <P>Recently, considerable interest have occurred in the development of an organic-inorganic-based bio-hybrid photodiodes (Bio-HPDs) with metal-free, eco-friendly, and cost-competitive features for light-sensitive devices. This paper reports a bio-inspired optical absorber material for the fabrication of Bio-HPDs using n-type hydrogenated amorphous silicon (a-Si:H) and a natural deoxyribonucleic acid (DNA)-cetyltrimethylammonium chloride (CTMA) biomaterial. a-Si:H is inexpensive and abundant, and DNA-CTMA is metal-free and eco-friendly. A DNA-CTMA coating on n-type a-Si:H leads to a chemically stable material with increased absorption and effective ties of dangling bonds and interface state density. Analysis results showed that the rectification ratio (RR) of the Bio-HPD is found to be 4 times higher than reference PD. This indicates that the effective RR is improved by the DNA-CTMA layer since it creates molecular charge interactions between DNA-CTMA layer and a-Si:H substrate. Moreover, Bio-HPD shows a light photosensitivity (I<SUB>photo</SUB>/I<SUB>dark</SUB>) of 474 with more reliable and has longer life time. In addition, the formation and feasible charge transport mechanisms are discussed. This biomaterial can be used for the development of commercially viable and environmentally safe large-scale Bio-HPDs applications.</P> <P><B>Highlights</B></P> <P> <UL> <LI> High-contrast DNA-CTMA/a-Si:H bio hybrid light-sensitive device fabricated. </LI> <LI> The photodiode parameters investigated by I–V measurements. </LI> <LI> XPS and XRD structural properties were examined. </LI> <LI> FTIR, Raman and UV–Vis measurements were used. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>
Reddy, M. Siva Pratap,Kwon, Mi-Kyung,Kang, Hee-Sung,Kim, Dong-Seok,Lee, Jung-Hee,Reddy, V. Rajagopal,Jang, Ja-Soon The Institute of Electronics and Information Engin 2013 Journal of semiconductor technology and science Vol.13 No.5
We have investigated the electrical properties of Ru/Ni/n-GaN Schottky structure using current-voltage (I-V) and capacitance-voltage (C-V) measurements at room temperature. The barrier height (${\Phi}_{bo}$) and ideality factor (n) of Ru/Ni/n-GaN Schottky structure are found to be 0.66 eV and 1.44, respectively. The ${\Phi}_{bo}$ and the series resistance ($R_S$) obtained from Cheung's method are compared with modified Norde's method, and it is seen that there is a good agreement with each other. The energy distribution of interface state density ($N_{SS}$) is determined from the I-V measurements by taking into account the bias dependence of the effective barrier height. Further, the interface state density $N_{SS}$ as determined by Terman's method is found to be $2.14{\times}10^{12}\;cm^{-2}\;eV^{-1}$ for the Ru/Ni/n-GaN diode. Results show that the interface state density and series resistance has a significant effect on the electrical characteristics of studied diode.
Siva Pratap Reddy Mallem,Peddathimmula Puneetha,Kalupudi Subramanyam,Varra Rajagopal Reddy,이동연,김영래,안성진,박귀일 한국화학공학회 2023 Korean Journal of Chemical Engineering Vol.40 No.4
Cubic-structured europium (Eu) doped zinc sulfide (ZnS) nanoparticles (NPs) were prepared via refluxing at 150 °C. Absolute structural studies showed that Eu+ ions were successfully substituted into the ZnS host lattice and changed the original structure of the host. As-fabricated ZnS:Eu NPs exhibited typical red emission due to the transition of the Eu dopant in the 5d0-7f1, 5d0-7f2, 5d0-7f3, and 5d0-7f4 energy levels of the 4f orbital of the dopant. The typical diamagnetic ZnS could be converted to tunable paramagnetic as a function of Eu-doping content. These NPs were quantified for hydrogen evolution through water splitting by artificial solar spectrum. Eu doping can drastically enhance the hydrogen (H2) evolution capability of ZnS, which is higher than that of bare ZnS NPs. The causes behind these engrossing results will be revealed. These interesting properties may find applications in optoelectronics, spintronics, and H2 evolution.
Reddy, M. Siva Pratap,Park, Herie,Lee, Jung-Hee Elsevier 2018 Optical materials Vol.76 No.-
<P><B>Abstract</B></P> <P>In this work, we present a residue-and-polymer-free graphene transfer method by using the adhesive force between graphene and a target substrate, the hydrophobic property of graphene, and the surface tension of the solutions. We used an n-type GaN substrate as the target substrate to make a photodiode (PD). Recently, the inclusion of biomolecules in photodetection technology has attracted considerable attention in the electronics and photonics research, particularly due to the rapid evolution of organic-inorganic bio-hybrid PDs (Bio-HPDs). This report presents a significant photoresponse of the bioinspired graphene-based PD fabricated with deoxyribonucleic acid-cetyltrimetylammonium chloride (DNA-CTMA) biomolecules on the n-type GaN substrate. Bio-HPDs respond to the infrared, visible, and ultraviolet wavelengths. Moreover, the Bio-HPDs show photosensitivities (I<SUB>photo</SUB>/I<SUB>dark</SUB>) of 21, 143, and 1194 for infrared, visible, and ultraviolet wavebands, respectively, which can be attributed to the integration of high-mobility graphene and photosensitive DNA-CTMA biomolecules. In addition, the corresponding charge transfer mechanisms in the PDs are explained by energy band diagrams.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Simple and cost-effective graphene transfer method is proposed. </LI> <LI> High-performance DNA-CTMA/graphene/n-GaN bio hybrid photodiode fabricated. </LI> <LI> The bio hybrid photodiode parameters investigated by I-V measurements. </LI> <LI> Transient photo characteristics were examined. </LI> </UL> </P>
M. Siva Pratap Reddy,Peddathimula Puneetha,이영웅,정성훈,박진호 대한금속·재료학회 2017 ELECTRONIC MATERIALS LETTERS Vol.13 No.1
Inthis work, a deoxyribonucleic acid-cetyltrimethylammoniumchloride (DNA-CTMA) biomaterial based p-type hydrogenatedamorphous silicon (a-Si:H) photodiode (PD) is fabricated and itselectrical characteristics are investigated. The Al/DNA-CTMA/p-type a-Si:H PD parameters are studied using current-voltage (I-V), capacitancevoltage-frequency (C-V-f) and conductance-voltage-frequency (G/ω-V-f)measurements. The barrier height and the ideality factor of the diode arefound to be 0.78 eV and 1.9, respectively. The electrical andphotoconductivity properties of the diode are analyzed by using dark I-Vand transient photocurrent techniques. The C-V-f and G/ω-V-fmeasurements indicate that the capacitance and conductance of the diodedepend on the voltage and frequency, respectively. The experimentalresults reveal that the decreases in capacitance and the increases inconductance with an increase in frequency can be explained on the basisof interface states (NSS). Series resistance (RS) measurements areperformed on the diode and discussed here. The obtained electricalparameters confirm that the Al/DNA-CTMA/p-type a-Si:H PD can beused as an optical sensor for the development of commercial applicationsthat are environmentally benign.