scholarly journals Enhancement of Photoluminescence Lifetime of ZnO Nanorods Making Use of Thiourea

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Erdal Sönmez ◽  
Kadem Meral
Keyword(s):  
Spray Pyrolysis Technique ◽  
Zno Nanorods ◽  
Optical Quality ◽  
X Ray Diffraction ◽  
Sem Images ◽  
Time Resolved ◽  
Structural Improvement ◽  
Exciton Lifetime ◽  
Photoluminescence Lifetime ◽  
Time Resolved Photoluminescence

We have investigated correlation of photoluminescence lifetime between zinc oxide (ZnO) nanorods and thiourea-doped ZnO nanorods (tu: CH4N2S). Aqueous solutions of ZnO nanorods were deposited on glass substrate by using pneumatic spray pyrolysis technique. The as-prepared specimens were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and time-resolved photoluminescence spectroscopy (TRPL). The photoluminescence lifetime of ZnO nanorods and ZnO nanorods containing thiourea was determined as  ns and  ns , respectively. The calculated lifetime values of ZnO nanorods revealed that the presence of thiourea in ZnO nanorods resulted in increasing the exciton lifetime. In addition to the optical quality of ZnO nanorods, their exciton lifetime is comparable to the longest lifetimes reported for ZnO nanorods. The structural improvement of ZnO nanorods, containing thiourea, was also elucidated by taking their SEM images which show the thinner and longer ZnO nanorods compared to those without thiourea.

Optical and Structural Properties of Fluorine Doped SnO2 on Si (100) for Photovoltaic Application

2018 ◽  
Vol 13 (10) ◽  
pp. 1522-1532 ◽  
Author(s):  
S. Nivetha ◽  
K. Kaviyarasu ◽  
A. Ayeshamariam ◽  
N. Punithavelan ◽  
R. Perumalsamy ◽  
...  
Keyword(s):  
Spray Pyrolysis Technique ◽  
Energy Difference ◽  
Vital Role ◽  
X Ray Diffraction ◽  
Energy Storage Devices ◽  
Sem Images ◽  
Storage Devices ◽  
Force Microscopy ◽  
Photovoltaic Application ◽  
Atomic Force

Photovoltaic material plays a vital role in the production of energy storage devices, more specifically in solar cell fabrications. In this work, ITO:F-doped materials were coated over the silicon substrate through spray pyrolysis technique. X-ray diffraction studies were conducted for porous silicon (PSi) coated with ITO:F structures formed at different current densities. This pore formation is evident from the broad peak at 69.9°, revealing an amorphous-like nature but at the same location where the single crystalline peak also is observed. These pores are explicitly shown in the SEM images in which very fine surface fragments are observed. At 20 mA/cm2, well-defined porous patterns that were uniformly distributed over the surface were observed. The microstructures observed via atomic force microscopy for these PSi coated with ITO:F structures are randomly aligned and almost evenly distributed over the entire surface of these nanorods, which are approximately 40 nm. Radiative recombination of electrons from a level in the conduction band or its subband to a level at an energy difference of greater than 1.7 eV in the valance band or its subband will emit visible light.

Plasmon Enhanced Emission of Perovskite Quantum Dot Films

MRS Advances ◽  
2018 ◽  
Vol 3 (14) ◽  
pp. 733-739 ◽  
Author(s):  
Seyma Dadı ◽  
Yemliha Altıntas ◽  
Emre Beskazak ◽  
Evren Mutlugun
Keyword(s):  
Quantum Dot ◽  
Au Nanoparticles ◽  
Au Nanoparticle ◽  
X Ray Diffraction ◽  
Time Resolved ◽  
X Ray ◽  
Transmission Electron ◽  
Coating Method ◽  
Photoluminescence Enhancement ◽  
Time Resolved Photoluminescence

ABSTRACTWe propose and demonstrate the photoluminescence enhancement of CsPbBr3 perovskite quantum dot films in the presence of Au nanoparticles. Embedded into a polymer matrix, Au nanoparticle- quantum dot film assemble prepared by an easy spin coating method enabled the photoluminescence enhancement of perovskite quantum dot films up to 78%. The properties of the synthesized perovskite QDs and gold nanoparticles have been analysed using high resolution transmission electron microscopy, X-ray diffraction, energy dispersive X- ray spectroscopy, UV-Vis absorption spectrophotometer, steady state and time-resolved photoluminescence spectrometer.

scholarly journals Time Resolved Optical Studies of InGaN Layers Grown on LGO

2002 ◽  
Vol 743 ◽  
Author(s):  
Maurice Cheung ◽  
Gon Namkoong ◽  
Madalina Furis ◽  
Fei Chen ◽  
Alexander. N. Cartwright ◽  
...  
Keyword(s):  
Structural Quality ◽  
Photoluminescence Intensity ◽  
X Ray Diffraction ◽  
Optical Studies ◽  
Time Resolved ◽  
Lattice Match ◽  
Spatially Resolved ◽  
Recombination Processes ◽  
Time Resolved Photoluminescence ◽  
Intensity Decay

ABSTRACTRadiative recombination processes in bulk InGaN grown by molecular beam epitaxy (MBE) on lithium gallate (LGO or LiGaO2) substrates were investigated using microscopic PL and time-resolved photoluminescence (TRPL). The improved structural quality resulting from a better lattice match of the LGO substrate to III-V nitride materials simplifies these investigations because well-defined composition phases can be analyzed for both homogeneous and phased separated InGaN samples. Epilayers of InGaN intentionally grown with and without indium segregation were studied. X-ray diffraction measurements showed that the homogeneous epilayer was high quality In0.208Ga0.702N and the segregated epilayer exhibited peaks corresponding to both In0.289Ga0.711N and In0.443Ga0.557N indicating the presence of higher In concentration regions in this sample. Spatially resolved photoluminescence spectra confirm the existence of these regions. The photoluminescence intensity decay is non-exponential for both samples and a stretched exponential fit to the decay data confirms the existence of local potential fluctuations in which carriers are localized before recombination.

Influence of Growth Conditions on Morphology of ZnO Nanorods by Low-Temperature Hydrothermal Method

2016 ◽  
Vol 675-676 ◽  
pp. 53-56
Author(s):  
Supawadee Pokai ◽  
Puenisara Limnonthakul ◽  
Mati Horprathum ◽  
Sukon Kalasung ◽  
Pitak Eiamchai ◽  
...  
Keyword(s):  
Aspect Ratio ◽  
Hydrothermal Method ◽  
Zno Nanorods ◽  
Cost Effective ◽  
Growth Conditions ◽  
Growth Time ◽  
Thermoelectric Device ◽  
X Ray Diffraction ◽  
Sem Images ◽  
X Ray

Zinc oxide (ZnO) nanorods (NRs) promise high potentials in several applications, such as photovoltaic device, thermoelectric device, sensor and solar cell. In this research, the vertical alignment of ZnO NRs was fabricated by hydrothermal method with various precursor concentrations and growth time on different seed layers (ZnO and Au), which deposited on silicon wafer substrate (100). The crystalline structure and morphology of ZnO NRs have been characterized by x-ray diffraction (XRD) and field emission scanning electron microscopy (FE-SEM) techniques, respectively. The x-ray diffraction pattern shows that the prepared samples have a strong preferred orientation (002) plane. FE-SEM images of the ZnO NRs, it found that the density and aspect ratio were strongly influenced by the seed layer and precursor concentration. In addition, the aspect ratio of ZnO NRs was increased with increasing growth time. This study provides a cost effective method for the fabrication of well aligned ZnO NRs for nano-electronic devices.

scholarly journals Synthesis of ZnO nanorods on ZnO/ITO seed layer by electrochemical method and its application in solar cell device

2013 ◽  
Vol 16 (4) ◽  
pp. 5-12
Author(s):  
Hoang Cao Son Tran ◽  
Khac Top Le ◽  
Duc Hao Nguyen ◽  
Thi Dong Tri Nguyen ◽  
Kien Quoc Luu ◽  
...  
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
Electrochemical Method ◽  
Zno Nanorods ◽  
Hybrid Solar Cells ◽  
X Ray Diffraction ◽  
Solar Cell Device ◽  
Sem Images ◽  
X Ray ◽  
Stable Flow

In this paper, we study on the effects of ZnO nanorods /seed ZnO on properties of hybrid solar cells. ZnO nanorods fabricated by electrochemical method of two-step stable flow of liquid Zn(NO3)2. 6H2O (0.005 M) and C6H12N4 (0.005 M). Morphology and optoelectronic properties of ZnO nanorods were studied by SEM images, UV-VIS transmission spectra, X-ray diffraction and photoluminescence spectrum. Elaboration of hybrid solar cells by inserting ZnO nanorods on organic photoactive layer of P3HT:PCBM and ITO, as result the solar cell conductivity performance is significantly improved. Experimental results show that ~ 1,392 mA/cm2 Jsc, Voc ~ 0.49 V, FF = 0.32, and PCE = 0.23%.

scholarly journals Фотолюминесценция с временным разрешением наноструктур InGaAs различной квантовой размерности

2019 ◽  
Vol 53 (11) ◽  
pp. 1520
Author(s):  
А.М. Надточий ◽  
С.А. Минтаиров ◽  
Н.А. Калюжный ◽  
М.В. Максимов ◽  
Д.А. Санников ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Quantum Well ◽  
Single Photon ◽  
Photon Counting ◽  
Dimensional Structure ◽  
Time Resolved ◽  
Single Photon Counting ◽  
Gaas Substrates ◽  
Photoluminescence Lifetime ◽  
Time Resolved Photoluminescence

By using time-correlated single-photon counting time-resolved photoluminescence of quantum-sized heterostructures of different dimensionality was investigated. InGaAs quantum dots, quantum well, and transitionally-dimensional structure — quantum well-dots were grown on GaAs substrates. It was observed, that photoluminescence decay strongly depends on structure dimensionality resulting in decay value of 6,7, and more than 20 ns for quantum dots, well-dots and well, respectively. As we believe localization centers in heterostructures may be responsible for such shortening of photoluminescence lifetime.

Enhancement of Photocatalytic Degradation of MB by Recyclable Li/Mn3O4 Thin films.

2021 ◽  
Author(s):  
M. A. Amara ◽  
T. Larbi ◽  
N. Mahdhi ◽  
Faycel saadallah ◽  
M. Amlouk
Keyword(s):  
Thin Films ◽  
Light Exposure ◽  
Spray Pyrolysis Technique ◽  
Photocatalytic Efficiency ◽  
X Ray Diffraction ◽  
Electrical Measurements ◽  
Sem Images ◽  
X Ray ◽  
Hydrophilic Character ◽  
Li Content

Abstract Thin films of physical--mixture of Hausmannite Mn3O4 and lithium (Li) are synthesized by spray pyrolysis technique. Structural, morphological, optical, electrical, wettability and photocatalytic properties have been investigated. X-ray diffraction (XRD) and Raman spectra, Scanning electron microscope (SEM) images and electrical measurements show that Li nanoparticles are formed both on top surface of the film and inside grain boundaries. Bandgap and Urbach energies and optical relaxation time have been determined from transmittance T and reflectance R spectra. Impedance spectroscopy shows that charge separation increases with Li content, which improves photocatalytic efficiency of the film. The best photocatalytic efficiency is obtained for Li/Mn ratio of 15%. Indeed, the degradation of methylene blue (MB) under ultraviolet (UV) and visible light exposure, is improved by a factor of 5.7 and 2.4 respectively, when compared to undoped Mn3O4. In addition, this film exhibits a high photostability (10 cycles consecutively) under solar light. On the other hand, hydrophobicity reveals the hydrophilic character of the films.

Controllable Synthesis and Photoluminescence Properties of ZnO Nanorod and Nanopin Arrays

2008 ◽  
Vol 8 (2) ◽  
pp. 993-996
Author(s):  
Song Yin ◽  
Yiqing Chen ◽  
Yong Su ◽  
Chong Jia ◽  
Qingtao Zhou ◽  
...  
Keyword(s):  
Zno Nanorods ◽  
Optical Quality ◽  
Zno Nanorod ◽  
X Ray Diffraction ◽  
X Ray ◽  
Electron Microscopies ◽  
Uv Emission ◽  
Transmission Electron ◽  
One Step ◽  
Zno Buffer Layer

Well-aligned ZnO nanorods and nanopins are synthesized on a silicon substrate using a one-step simple thermal evaporation of a mixture of zinc and zinc acetate powder under controlled conditions. A self-assembled ZnO buffer layer was first obtained on the Si substrate. The structure and morphology of the as-synthesized ZnO nanorod and nanopin arrays are characterized using X-ray diffraction, and scanning and transmission electron microscopies, energy-dispersive X-ray spectroscopy, and photoluminescence spectroscopy. The influence of the background atmosphere on the two ZnO nanostructures has been studied. Two different growth mechanisms are mentioned to interpret the formation of ZnO nanorod and nanopin arrays in our work. The room-temperature PL features the ZnO nanorods exhibit only sharp and strong ultraviolet (UV) emission emissions, which confirms the better crystalline and optical quality than the ZnO nanopins.

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