http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
- 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
- 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
RISS 인기검색어
- 검색키워드
- 저자 : Haranath D. (검색결과 4 건)
- 무료
- 기관 내 무료
- 유료
-
Jayasimhadri, M.,Jha, Kaushal,Ratnam, B.V.,Woo, Hyun-Joo,Jang, Kiwan,Rao, A.S.,Haranath, D. ELSEVIER SCIENCE 2017 JOURNAL OF ALLOYS AND COMPOUNDS Vol.711 No.-
<P><B>Abstract</B></P> <P>In this work, Tb<SUP>3+</SUP> ions doped lead-germanate-tellurite (LGT) glasses were prepared by conventional melt quenching technique with different dopant concentrations ranging from 0.5 to 3.5 mol %. X-ray diffraction (XRD) and FT-IR analysis were carried out to analyze the structural properties of LGT glass. The excitation spectra revealed a single band centered in the NUV region at 380 nm by monitoring emission at 545 nm. The emission spectra consist of four bands, which are attributed to the <SUP>5</SUP>D<SUB>4</SUB>→<SUP>7</SUP>F<SUB>J</SUB> (J = 3–6) transitions. Among these transitions, the strong emission band was observed at 545 nm corresponding to the <SUP>5</SUP>D<SUB>4</SUB>→<SUP>7</SUP>F<SUB>5</SUB> transition and the optimized doping concentration of Tb<SUP>3+</SUP> ions was 2 mol %. The Huang's theory and I-H model indicate the possibility of energy transfer via electric dipole-dipole interaction between Tb<SUP>3+</SUP> ions. The CIE chromaticity coordinates were (<I>x</I> = 0.282 and <I>y</I> = 0.614) and emits intense yellowish green light. The decay curves measured for <SUP>5</SUP>D<SUB>4</SUB> level for the samples with different doping concentrations and the lifetime for the optimized sample was 548 μs. The results indicate that these glasses have potential applications in solid state lighting and display devices.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Optically transparent Tb<SUP>3+</SUP> doped PbO-GeO<SUB>2</SUB>-TeO<SUB>2</SUB> (LGT) glasses have been prepared. </LI> <LI> Excitation spectrum consists of single band in the NUV region at 380 nm. </LI> <LI> CIE coordinates indicate that Tb<SUP>3+</SUP> doped LGT glass emits yellowish green light. </LI> <LI> Huang's theory applied to reveal the energy transfer process between Tb<SUP>3+</SUP> ions. </LI> <LI> This glass may be potential to use in fabricating GaN based WLEDs. </LI> </UL> </P>
-
Bandgap Engineering and Doping of ZnO and ZnOS Nanocrystals
Rameshwar N. Bhargava,D. Haranath,Adosh Mehta 한국물리학회 2008 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.53 No.5
For the first time doped ternary nanocrystals have been synthesized with high luminescent efficiency. The energy band-gap of ternary ZnO1-xSx alloy shows significant band-gap bowing. The band-gap of ZnOxS1-x alloys can be varied from 360 nm to 470 nm suggesting that these ternary nanophosphors are an excellent choice for white light generation from UV/blue LEDs.
-
Vikas,Jayasimhadri M.,Haranath D. 한국물리학회 2024 Current Applied Physics Vol.58 No.-
Transparent, Eu3+ doped potassium tungstate tellurite (TKWZBiEu) glass matrices were successfully synthesized via employing the traditional melt quenching method and their thermal, structural and photoluminescent characteristics were thoroughly investigated. To estimate the aggregate weight loss, glass transition temperature (Tg) and thermal stability factor (ΔT) of the prepared host glass matrix, thermogravimetric analysis-differential scanning calorimetry (TGA-DSC) were utilized. The non-crystalline character of the prepared TKWZBiEu glass was studied via XRD profile. Various vibrational functional groups were revealed via employing Fourier transform infrared (FT-IR) spectroscopy. The optical bandgap (Eopt) values for all prepared TKWZBiEu glasses have been evaluated by employing the absorption spectra. Under n-UV and blue excitations, all the prepared TKWZBiEu glasses are demonstrating reddish emission at 614 nm ascribed to the 5D0 → 7F2 transition, in which the intensity is increasing continuously with Eu3+ ion content up to 5.0 mol%. The experimental lifetime (τ) profiles demonstrate the single-exponential nature of prepared TKWZBiEu glasses under n-UV excitation. Furthermore, temperature dependent photoluminescence (TDPL) spectra indicate excellent thermal stability of the TKWZBiEu glass matrix with the highest value of activation energy (ΔE). The prototype organic epoxy resin/ binder-free device has been developed using the 5.0 mol% Eu3+ doped with TKWZBi glass matrix and n-UV LED chip. All the aforementioned findings validate that the optimized TKWZBiEu glass is an auspicious candidate for the red component to fabricate organic epoxy-free w-LEDs.
-
The effect of carbon nanotubes (CNT) on thermoelectric properties of lead telluride (PbTe) nanocubes
B. Khasimsaheb,Niraj Kumar Singh,Sivaiah Bathula,Bhasker Gahtori,D. Haranath,S. Neeleshwar 한국물리학회 2017 Current Applied Physics Vol.17 No.2
We report the thermoelectric properties of different weight percentage of carbon nano tubes (CNT) dispersed (0.025, 0.05 and 0.1%) in PbTe nanocubes matrix. The sample with 0.05% CNT distribution in the PbTe matrix significantly enhanced the electrical conductivity, and Seebeck coefficient above 450 K. In this system CNT’s acting as a low energy filter at potential barrier and good passage for high energy electron which may cause enhance the electrical conductivity. Mixing of CNT into PbTe nanocubes created numerous additional interfaces which are acted as scattering centers for phonons and thus resulted in ultra low thermal conductivity of 0.24 and 0.32 W/m K at 525 K for 0.025 and 0.05% CNT dispersed PbTe matrix, respectively. An optimum quantity of CNT addition to PbTe enhanced the zT ~0.11 at 525 K for both 0.025 and 0.05% CNT dispersed PbTe matrix, respectively, which is 90% higher in comparison to PbTe nanocubes. Finally, CNT’s dispersed PbTe nanocomposite exhibited good thermoelectric compatibility factor and these materials are good candidate materials for segmentation to get maximum power output during power generation applications.
연관 검색어 추천
이 검색어로 많이 본 자료
활용도 높은 자료
