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Development and Testing of Photoanode Materials for Dye Sensitized Solar Cells

Thesis Info

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Author

Muhammad, Niaz

Program

PhD

Institute

Quaid-I-Azam University

City

Islamabad

Province

Islamabad.

Country

Pakistan

Thesis Completing Year

2018

Thesis Completion Status

Completed

Subject

Physical Sciences

Language

English

Link

http://prr.hec.gov.pk/jspui/bitstream/123456789/11606/1/Niaz%20Muhammad_Chem_2018_QAU_PRR.pdf

Added

2021-02-17 19:49:13

Modified

2024-03-24 20:25:49

ARI ID

1676724610695

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This thesis describes the purposeful fabrication of TiO2 photoanode based dye sensitized solar cells (DSCs) and their detailed characterization. The aim was to investigate the structural function relationship of the photoanode on the photovoltaic performance of the devices. The hierarchical anatase TiO2 microspheres (Tmic) and nanoparticles (Tnano), with an average particle size of 0.38 µm and 20 nm, were synthesized by low cost solution and hydrothermal methods, respectively. Highly screen printable pastes of the Tmic and Tnano have been developed to prepare bifunctional films, with increased light scattering and large surface area, for the solar cells. These advantageous properties of TiO2 microspheres were evidenced by the evaluation of electrochemical and photoelectrochemical characterization. In the DSCs, these films lead to a 32% increase in conversion efficiencies when compared to those with the films of TiO2 nanoparticles only. The efficiency was further improved by TiCl4 post-treatment. In the second part of the study, the anatase TiO2 microspheres were annealed at elevated temperature of 500 oC and 900 oC for one hour in order to obtain highly crystalline and phase pure anatase and rutile TiO2 microspheres, respectively. These microspheres were used as the upper light scattering layer in a double layered structure with Tnano as the lower dye sensitization layer in anatase phase. Remarkable improvement of 48 % and 58 % in the power conversion efficiency was recorded for anatase and rutile microspherical TiO2 scattering layers respectively, in comparison to the devices having no scattering layer composition. In particular, the performance of rutile TiO2 microspheres as light scattering layer was quite high (6.3 %) due its high refractive index (2.79) than the anatase phase (2.54). Thirdly, to further improve the efficiency of the DSCs based on double layered photoanodes, the compact blocking layers were introduced beneath the absorber layer. The blocking layers of TiO2 and ZnO/TiO2 were deposited on FTO surface by electrostatic layer by layer deposition method at room temperature. These blocking layers physically blocked the access of redox electrolyte and retarded the electron back reaction at FTO/meso-TiO2/electrolyte interface.A considerable increase in electron life time (18 ms to 42 ms) was observed with these DSCs which resulted in larger short circuit current densities and higher overall power conversion efficiencies up to 9.0 %. In the fourth part of investigation, the results of differently modified pastes, using commercial TiO2 nanoparticles as the major component, have been presented. The focus iii was on the optimization of the concentration of binders and the rheological agents to develop high quality screen printed TiO2 films. The properties discussed include the porosity, cracks and aggregates, connectivity of the particles, their strong adherence to FTO surface, charge transport, and the dye uptake ability. Among the various pastes, the best paste was utilized for the screen printed photoanodes, to optimize the film thickness and the annealing temperature. The best photovoltaic performance was achieved with three layers of commercial TiO2 film of 15 µm thickness and annealed at 500oC. Finally, in the light of findings of the present research work and overall literature review, the worldly established overall certified power conversion efficiency (13%) achieved by DSCs at laboratory scale and submodule level so far in comparison to other competent solar cell technologies have been summarized.Further, the prospect of future development of DSCs to become industrially mature technology has been presented by analyzing the different challenges that needs to be carefully controlled.
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مولوی محبوب عالم

مولوی محبوب عالم
اس ماہ کے شذرات کا صفحہ وفات نامہ ہوا چاہتا ہے، مگر احسان فراموشی ہوگی اگر ملک کے سب سے بوڑھے صحیفۂ نگار مولوی محبوب عالم اڈیٹر پیسہ اخبار لاہور کا ماتم نہ کیا جائے، ۲۸؍ مئی کو انہوں نے اس دارِ فانی کو الوداع کہا، وہ اردو کے سب سے پہلے روزنامہ اخبار (پیسہ) کے اڈیٹر تھے، انہوں نے صرف اپنی محنت و کوشش سے سرمایہ حاصل کیا اور ملک میں تاریخ اور سیاحت ناموں کے پڑھنے کا ذوق پیدا کیا اور خود بھی یورپ اور ممالک اسلامیہ کے دوسفر کئے اور سیاحت نامے لکھے، مگر افسوس کہ اب ان کو وہ سفر پیش آیا جس کا سفرنامہ انسانوں کے ہاتھ نہیں، فرشتوں کے ہاتھ لکھتے ہیں، اس ان دیکھی منزل کے بوڑھے مسافر پر اﷲ تعالیٰ کی رحمت ہو۔
مرحوم نے ۷۴ برس کی عمر پائی۔ (سید سلیمان ندوی، جولائی ۱۹۳۳ء)
تصحیح: منشی محبوب عالم مرحوم کے تذکرہ میں یہ لکھا گیا ہے کہ وہ اردو کے پہلے روزانہ اخبار کے بانی اور اڈیٹر تھے، اس سے مراد مسلمانوں میں تھی، یعنی اردو کے پہلے اسلامی روزانہ اخبار کے وہ بانی اور اڈیٹر تھے، اردو میں منشی نولکشور لکھنو کا اودھ اخبار ان کے اخبار سے پہلے نکلا تھا اور اب تک نکل رہا ہے۔ (سید سلیمان ندوی، اگست ۱۹۳۳ء)

 

تابوت سکینہ کی تلاش کا سبب

Lexical investigation of words/selected passages of Quran is among many ways of exegesis of Quran. Such work is compiled on the basis of an extensive analysis of the text of the Quran and consideration of lexical examination of Quranic words. Specialized works on aspects of Quranic vocabulary has been in the tradition of Islamic scholarship right from the beginning and there are a number of works that help in the etymological & philological understanding of difficult words of Quran.  The classic text by al-Raghib al-Isfahani named, Mufradat, is the best example of books that treat difficult words in the Quran. In this article, we have presented information regarding the works of scholars of Indian sub-Continent on the subject of Mufradat al-Quran (Selected passages of Quran). We have found that South Asian Scholars have written books abundantly in the field of Mufradaat and Luhgaat al Qur’an, in Arabic, English, Persian, Sindhi & Urdu languages. This study covers in detail an overview of the acclaimed works of subcontinent scholars which mainly split into precise and concise written books on the topic of Mufradat al Qur’an. Forty-eight books have been introduced in below pages. Our work is 1st step towards complete indexing of such works of Sub-continent scholars for easy access of scholars and researchers who want to do some research in this area.

Politico-Economic Significance of Gwadar Port: Implications for Regional Integration

“Whoever controls the Indian Ocean dominates Asia. This Ocean is key to the seven Seas in the twenty first century, the destiny of the world will be decided in these waters” stated US Rear Admiral Alferd Thayer Mahan. This indicates geo-strategic importance of Indian Ocean. Pakistan is located on the Indian Ocean which connects the landlocked Central Asian Republics with the Sea. Gwadar is a coastal town of Baluchistan, a province of Pakistan, which remained a part of Oman for more than 150 years i.e., 1784 to 1958. Later on, due to its significance, it was bought back by Pakistan with payment of £ 3 million. The city came under the limelight of Pakistan’s policy makers as 35 % of international oil is transporting near it. It was visualized as a hub port for the region when it became part of Pakistan, but financial and technical issues prevented the dream to be materialized. The project remained in papers until China promised to provide financial assistance. The former president of Pakistan Parvez Musharraf during his visit to China in May 2001, requested Chinese government to help in the project. On 22nd March 2002, the project was inaugurated by Pakistan’s president Musharraf and Chinese Prime Minister Wu Gang Guo. The port was then handed over to Port Singapore Authority on 6th February 2007 after its completion in 2006. Port Singapore Authority failed to upgrade the port on promised lines 18th February, 2013 the port was handed over to Chinese Overseas Port Holding Company (COPHC). The geography of the port has attracted the players because of which the situation worsened. The economic potential of the port is the key interest for these players. The port could also be used as naval base in time of exigencies. Situation of confusion would arise in case of converting of Gwadar port into a naval base either by China or USA. Overlapping of economic, political and strategic interests of the involved actors make the area very sensitive. Iran and India have their own plan of action in the region. There is another challenging confusion engineered by China and USA with the clash of their interest in the region that could be reduced or subsided by the frequent use of diplomatic channels. China and USA, under the paradigm of their policies, are promoting their interests in the region and there will be collaboration in future. Landlocked Central Asia and Afghanistan are depending on the port to marketise their resources. Conventional theory of integration defines regional integration as a trade creation and the port has the ability to create trade. Trade creation means shifting of local production with a high cost to member nations low cost products in a regional block. Generally, economic integration is the outcome of an evolutionary course of regional cooperation. European Union is the best example which became a political Union after completion of its economic integration. In order to bring regional countries on a single platform, different steps like free trade zones and tax relaxation are taken by the respective governments; these would be followed by steps like open border system common currency and extended people to people contacts in the region in future. CPEC is the best example of these steps. Iran, a strong competitor wants to be a part of the project. TAPI, IPI and TAP are the proposed projects which when materialized will bring integration to the regional countries. The port at Gwadar is located at the confluence of two main regions, the oil rich Central Asia and emerging consumer market South Asia. The port is located on a point which provides a strategic depth to Pakistan against her adversaries. The port has the ability to check Sea Lanes of Communication during war and peace. Due to geo-strategic importance of the port, all regional and extra-regional players have keen interest in it. Central Asia hopes to export its riches through it while United States of America with diverse demands wants to ensure its presence there. Each player has its own objectives with different approach to accomplish. Having tremendous importance, the port has become a flash-point and Pakistan has to reconsider the situation in terms of its priorities. Major objectives of the study are to expose economic and strategic importance of Gwadar port and to find out its impacts on regional integration. To achieve the mentioned objective, empirical, descriptive, analytical and predictive methodology is applied. The bulk of the study attained through the analysis of documents, books, electronic journals, and scholarly papers, including textual interpretation or ‘content analyses’ as well. Textual interpretation used to summarize, and identify the main properties of the text; and then evaluate the text. This research concludes that cooperation among the concerned states and peace in Afghanistan would bring economic integration in the region which would automatically be followed by political harmony among the regional countries. One important recommendation in this regard is that Pakistan has to formulate policies to avoid confrontation of major players and all the related players. Especially, the potential powers should accommodate each other’s interests in the larger interest of the region.