Search or add a thesis

Advanced Search (Beta)
Home > Growth and Characterization of Doped Metal Oxide Nanostructured Thin Films

Growth and Characterization of Doped Metal Oxide Nanostructured Thin Films

Thesis Info

Access Option

External Link

Author

Shaukat, Saima

Program

PhD

Institute

University of Engineering and Technology

City

Lahore

Province

Punjab

Country

Pakistan

Thesis Completing Year

2016

Thesis Completion Status

Completed

Subject

Physics

Language

English

Link

http://prr.hec.gov.pk/jspui/bitstream/123456789/12672/1/Saima%20Shaukat_Phy_2016_UET%28L%29_PRR.pdf

Added

2021-02-17 19:49:13

Modified

2024-03-24 20:25:49

ARI ID

1676726346378

Asian Research Index Whatsapp Chanel
Asian Research Index Whatsapp Chanel

Join our Whatsapp Channel to get regular updates.

Similar


Nanostructured materials including variety of metals and semiconducting oxides in the field of one dimensional (1-D) nanostructure have fascinated great attention from both fundamental basis and technological points of view. Zero (0-dimensional) and one dimensional (1-D) nanostructured metal oxide thin films including nanostructures, such as nanobelts, nanowires, nanotubes, nanorods, nanopyramids and nanospheres etc. have gained incredible consideration for their potential applications in optoelectronic as well as in electronic technology within the last decade. Some fundamental facts and phenomena related to 1-D nanostructures are still not cleared for example, high surface to volume ratio in semiconductors demonstrate surprising growth architecture, e.g. temperature and diameter-dependent growth directions, strange doping levels and organization, which are still not known for their macroscopic crystals or thin-film counterparts. The incorporation of metallic nanoparticles in semiconductor materials not only customize its properties but also breed a collective new event based on interaction of both at interface. The addition of external metallic ions through any means can promote charge separation effectively and also improve light absorption in the semiconductor. In this thesis, state-of-the-art approaches and strategies for shaping of one-dimensional functional semiconductors can be used for variety of applications including sensors, actuators, optoelectronics, spintronic, biomedical sciences and energy harvesting fields. Amongst semiconducting metal oxide nanomaterials, Chromium Dioxide (Cr2O3), Zinc Oxide (ZnO), and Tungsten oxide (WO) are important and most promising candidates for use as functional building blocks in wide range of applications, based on the fact that they are the best candidates for structural, chemical, optical and transport properties for use in optical and electrochemical devices. These novel materials with unique physical and chemical properties have been significantly assigned to their distinctive structural aspects in between the isolated quantum atoms and the bulk macroscopic materials. Upto now, various doping elements may n or p-type have been studied as a dopant in metal oxides to improve their conductivity and stability at high temperatures. For example, n type or p-type dopant elements exploit the properties of the host oxide and manipulate conductivity by generating surplus or deficiency in the valence electrons. In this project, we successfully report the production of fractal type one dimensional (1-D) semiconductor nanostructures including (nanosheets, nanotriangles, nanodiamond like octahedrons, nanoflakes, nanowires, nanopillars, nanocauliflowers, nanospheres and nanopyramids) of Cr2O3, ZnO and WO doped with transition metals including Nickel (Ni), Niobium (Nb), Germanium (Ge), Gold (Au), Zirconium (Zr) and Multiwalled Carbon Nanotubes (MWCNTs) as dopant elements to tailor the structural, morphological, vibrational, optical and transport properties of host oxides. We utilized Pulsed Laser Deposition (PLD) technique for the growth of Ni doped Cr2O3 thin films whereas Aerosol assisted chemical vapor deposition (AACVD), a chemical solution based method is used to synthesize semiconducting metal oxide nanowires, nanospheres, nanopillars, nanocauliflowers, nanoflakes and nanopyramids in doped Zinc Oxide (ZnO) and Tungsten Oxide (WO). The morphological properties, crystalline structure, chemical composition and optical behavior are presented to understand the fundamentals involved in the growth of 1-D nano architecture. We investigate the parameters which control the nucleation, organization and evolution of these multifaceted structures providing new insights to the stepwise homogeneous mechanism and the conventional nucleation performed by the metallic ions. In recent years, one of the variant of CVD called aerosol assisted chemical vapor deposition (AACVD) provides a wide range and choice of precursors which are soluble in solvents. Also the delivery of the precursors is very simplified and easy for different chemical sources to transport e.g. species of Zn, O and any doping through single line. The architecture of AACVD grown thin films for optoelectronic devices can be tailored by the suitable choice of substrate, physical aspects of solute and solvent, type of carrier gas and growth environment i.e. substrate temperature. The most critical parameters during deposition in aerosol assisted CVD involves the maintained substrate temperature and duration which can affect the quality of nanostructures. Under consideration of these parameters, we have successfully deposited coatings and produced nanoarchitecture of doped metal oxide nanostructured thin films of Cr2O3 using PLD (at temperature of 450°C onto silicon, 1 0 0), ZnO and WO using AACVD (at temperature of 400°C onto silica) via methanol and toluene. Various metalorganic sol of precursors was considered for their viability in yielding doped zinc oxide nanohierarchical architecture by AACVD, potentially active in the market of transparent conductors. Electrical conductivities of the grown nanostructures were observed to be ineffective for use in TCO; however, nanostructured thin films produced from precursor of zinc acetate [Zn (C2H3O2)2] showed high transparency in the visible (VIS) and infrared (80-90) % region with preferential orientation along (0 0 2) or c-axis growth. All deposited nanostructured thin films presents fluctuating surface morphology, crystallite orientations which were subjected to the experimental conditions e.g. substrate temperature during deposition and choice of doping. The outcomes of this project involves the success in tailoring of densely packed fractal type nanostructures including nanosheets, nanodiamond like octahedrons for the first time reported in literature, nanowires, nanospheres, nanopyramids, nanopillars and nanocauliflowers with improved structural, morphological and functional (optical and electrical) properties for use in technological applications e.g. optoelectronics and gas sensors. Rarely developed nanopyramids and nanotriangles of ZnO and Cr2O3 in this project potentially can be used in thin film solar cells of silicon community, because firstly this pyramidal architecture can meritoriously enhance scattering of light that can probably increases the absorption of light being absorbed by the cell and secondly such type of hierarchical structures can easily be prepared by simple approaches based on solution dynamics and powder metallurgical methods rather than expensive vacuumcentered techniques. Later, nanoarchitecture of Zinc Oxide (ZnO) and Tungsten Oxide (WO) were redeposited onto sensor substrate using AACVD. All patterned undoped and doped metal oxide sensors were tested at various gases to investigate the detection of toxic trace elements that is also a future task.
Loading...
Loading...

Similar Books

Loading...

Similar Chapters

Loading...

Similar News

Loading...

Similar Articles

Loading...

Similar Article Headings

Loading...

جغرافیائی تناظر

سیالکوٹ پاکستان کا ایک قدیم شہر ہے۔یہ ۳۲ درجے ۳۰ دقیقے عرض بلد شمالی اور ۷۴ درجے ۳۲ دقیقے طول بلد پر واقع ہے۔یہ سطح سمند ر سے ۸۰۰ فٹ بلند ہے۔(۱)اس کے شمال میں ضلع گجرات اور جموں کا علاقہ ہے۔جنوب میں بھارت کا ضلع امر تسر ،مشرق میں ضلع گورداس پور،مغرب میں ضلع شیخوپورہ اور جنوب مغرب میں ضلع گوجرانوالہ ہے۔(۲) مغرب میں دریائے چناب ضلع سیالکوٹ اور ضلع گجرات کے درمیان بہتا ہے ۔سیالکوٹ رچنا دو آب میں (دریائے راوی اور چناب کے درمیان)واقع ہے اوراس کا بالائی حصہ (جو کوہ ہمالیہ کی تلہٹی میں واقع ہے) بہت زرخیز ہے۔جنوبی حصہ نسبتاً کم زرخیز ہے۔(۳)شہر کے شمال سے گزرنے والے دریائے چناب کے سوٹے کوہ ہمالیہ سے پھوٹتے ہیں ۔یہ قدیم دریا عوامی جمہوریہ چین کے قریب سے شروع ہوتا ہے۔قدیم زمانے میں اس دریا کو ’’چین آب ‘‘ کے نام سے پکارا جاتا تھا۔جو زمانے کے ساتھ ساتھ تبدیل ہوتا ہوا آج دریائے چناب کہلاتا ہے۔یہ دریا جموں کشمیر کے پہاڑی علاقوں سے گزرتا ہوا جب ضلع سیالکوٹ میں داخل ہوتا ہے تو ہیڈ مرالہ کے مقام پر یہاں اس میں دو اور دریا اٹھکیلیاں کرتے اور زندگی کی بہاریں تقسیم کرتے آکر مل جاتے ہیں۔یہ دریائے جموں توی اور دریائے (مناواں) مناور توی ہیں۔(۴)

          دریائے چناب میں مرالہ کے مقام پر بند باندھ کر نہر اپر چناب نکالی گئی ہے۔اس نہر کی تین شاخیں ہیں۔ایک شاخ کا پانی تحصیل ڈسکہ اور باقی دو شاخوں کا پانی ضلع گوجرانوالہ کے کھیتوں کو سیراب کرنے میں استعمال ہوتا ہے۔نہر مرالہ راوی لنک ضلع سیالکوٹ کے مغربی حصے کو سیراب کرتی ہے اور جو پانی باقی بچ جاتا ہے۔اس لنک کے ذریعے دریائے راوی میں چلا جاتا ہے تاکہ دریائے راوی سے نکلنے والی نہر اپر باری دو آب...

ANALISIS NILAI-NILAI TOLERANSI DALAM BUKU “SENANG BELAJAR AGAMA ISLAM DAN BUDI PEKERTI” DI KELAS IV DAN V SD DI KAB. KARANGANYAR “SENANG BELAJAR AGAMA ISLAM DAN BUDI PEKERTI” DI KELAS IV DAN V SD DI KAB. KARANGANYAR

Oleh Rizky Martha Oktavia Prodi Pendidikan Agama Islam, Pascasarjana, IAIN Surakarta rizkymarthaoktavia@gmail. Com   Abstrak Kesuksesan pendidikan toleransi melalui pendidikan agama Islam dapat ditopang oleh komponen bahan ajar, misalnya buku “Senang Belajar Agama Islam dan Budi Pekerti” bagi Siswa Kelas IV dan V SD di Kab. Karanganyar. Permasalahannya, bagaimana analisis nilai-nilai toleransi dalam buku tersebut? Tujuan penelitian, yaitu menganalisis nilai-nilai toleransi dalam buku “Senang Belajar Agama Islam dan Budi Pekerti” bagi Siswa Kelas IV dan V SD di Kab. Karanganyar. Dengan pendekatan kualitatif dan jenis penelitian pustaka, data penelitian berupa nilai-nilai toleransi diperoleh dari sumber data buku dikumpulkan dengan studi dokumentasi. Keabsahannya diperiksa dengan teknik (1) triangulasi, (2) pengecekan anggota, (3) meningkatkan ketekunan, dan (4) kecukupan bahan. Berdasarkan hasil analisis isi ditemukan nilai-nilai toleransi, yakni 31 nilai toleransi, misalnya (1) tidak menertawakan cara beribadah umat beragama lain, (2) tidak membicarakan kekurangan agama umat beragama lain, (3) tidak mencela aturan beribadah umat beragama lain. Saran kepada penulis buku Pendidikan Agama Islam (PAI) SD, yakni perlu penyebaran nilai toleransi pada setiap bab; guru PAI dan siswa kelas IV dan V SD perlu membaca, bahkan menelusuri nilai toleransi agar dapat diajarkan berkelanjutan; siswa kelas IV dan V SD perlu membaca dan menerapkan nilai toleransi dalam buku dengan berkonsultasi pada orang tua dan guru yang membinanya; kepala SD dapat menjadikan sebaran nilai-nilai toleransi sebagai panduan untuk memilih, menentukan, dan merancang kegiataan sosial kemasyarakatan di sekolah untuk melatih kepekaan siswa menjadi generasi yang toleran. Kata-kata Kunci: nilai toleransi, budi pekerti, pendidikan                               agama Islam

Nato After 9/11: Role in War Against Terrorism

The study examines actions and decisions of the NATO, in reaction to the 9/11 terrorist attacks and assesses role of the member states in combating global terrorism. Focus of the study is: first, on role the NATO played in the war against terrorism and second, the impediments that restrained a bigger global role of the alliance in this conflict. The study begins with the brief account of NATO transition from Cold War to post-9/11 era, followed by examination of the alliance’s response to 9/11 terrorist attacks including acquisition of essential capabilities for responding to global threat of terrorism. It then analyses role of NATO’s ISAF mission in Afghanistan, main motivations behind the decisions of the alliance members to contribute for the mission and its core objectives in fighting terrorism. After the broad overview of the NATO role in war on terror, main obstacles to such a bigger role of the alliance are analyzed. As a response to 9/11 terrorist attacks, instead of giving initiative to the alliance, the United States decided to lead a coalition of willing against the terrorists of AlQaeda and their supporters in Afghanistan. It became obvious during the conduct of “Operation Enduring Freedom” that leadership of the United States never wanted operations against terrorists to be dominated by alliance’s consensus building process. Lessons of the alliance role in Balkan crisis and gap in the military capabilities between America and its European allies possibly motivated the United States to avoid alliance’s constraints. Contributions of NATO to Operation Enduring Freedom and ISAF included deploying Naval Forces to the Eastern Mediterranean, deploying Airborne Warning and Control Systems (AWACS) for surveillance of U.S airspace, taking preventive measures against terrorism, sending military forces to Afghanistan in support of U.S efforts in war against Al-Qaeda and its supporters, conducting stabilization/ development/ humanitarian relieve operations in Afghanistan and providing training to Afghan Security Forces. Responses of NATO to the asymmetric and unconventional threat of global terrorism, and the combat and non-combat contributions that the alliance members could make in fighting terrorism, support the central hypothesis examined in this study: that the NATO is no more a single threat-specific and defensive alliance but adopted itself to the new realities and emerging threats