Full metadata record
| DC Field | Value | Language |
|---|---|---|
| dc.contributor | School of Fashion and Textiles | en_US |
| dc.contributor.advisor | Tao, Xiaoming (SFT) | en_US |
| dc.creator | Balilonda, Andrew | - |
| dc.identifier.uri | https://theses.lib.polyu.edu.hk/handle/200/14096 | - |
| dc.language | English | en_US |
| dc.publisher | Hong Kong Polytechnic University | en_US |
| dc.rights | All rights reserved | en_US |
| dc.title | Fiber-shaped perovskite solar cells for high performance solar fabrics | en_US |
| dcterms.abstract | The advancement of fabrication technologies and the miniaturization of electronic devices triggered the rise of wearable electronics. However, these devices require substantial amount of power, which puts strain on the main power grids. To address this issue, fiber-shaped solar cells have emerged as a solution, providing self-powered devices and flexible/bendable photovoltaic systems. Fiber-shaped solar cells offer a multitude of advantages due to their unique geometry. Their increased flexibility allows for versatile applications, making them ideal for integration with various devices and structures. The lightweight makes them easy to handle, while their ability to conform to the human body and other shapes opens up new possibilities for wearable technology and architectural design. These innovative solar cells provide a sustainable and aesthetically pleasing solution for capturing solar energy in a wide range of settings. As a result, there is increasing need for highly efficient and stable fiber-shaped solar cells and solar fabrics to power portable and wearable electronics. | en_US |
| dcterms.abstract | A crucial component of any solar cell is the photovoltaic layer. Perovskite, a new photovoltaic material, offers extraordinary energy conversion efficiency, and can be processed using solution-based methods. This presents an opportunity to develop low-cost and high-performance fiber-shaped solar cells. | en_US |
| dcterms.abstract | Despite the remarkable power conversion efficiency (PCE) beyond 25.5%, perovskite solar cells, especially the Sn-based variants lack stability compared to silicon solar cells. Hybrid 2D/3D perovskite materials offer a solution to the stability issue in solar cells without compromising efficiency, with record stability of > 1 year. However, the reaction between 2D and 3D perovskite molecules requires high temperatures (~300°C) and increased reaction time (~24 hours) to achieve high-quality 2D3D hybrid perovskites. In the first part our study, we based on the ability of chlorine to displace iodine from its ionic compounds in solutions to utilize chloride ions as catalysts for speeding up the reaction between iodine-based 2D and 3D perovskite molecules. By using this method, high-quality 2D3D hybrid material formed in a short time and a low temperature ~ 100°C. Integrating the synthesized and optimized hybrid perovskite material in a fiber-shaped solar cell architecture yielded the high PCE of 11.96% in Sn-based fiber-shaped perovskite solar cells. The unencapsulated and encapsulated fiber-shaped solar cells could maintain 75% and 95.5% of their original PCE respectively, after 2000 hours under room light and relative humidity of 35-40%. | en_US |
| dcterms.abstract | To further improve the performance and stability of fiber-type Sn-based perovskite solar cells, the second part of our study focused on minimizing the oxidation of Sn-based perovskite materials, which results into material degradation. Sn-based perovskite materials have gained attention as an alternative to Pb-based materials in order to address the issue of toxicity in perovskite solar cells. However, Sn-based perovskite solar cells are known for their poor stability and loss of efficiency due to the rapid oxidation of Sn2+ to Sn4+ when exposed to air. Various antioxidants have been proposed to slow down the oxidation process. Nevertheless, during the antioxidation process, the antioxidant itself undergoes oxidation and forms non-antioxidizing byproducts. This occurs in a single-stage redox reaction, depleting the antioxidants quickly and diminishing their ability to prevent oxidation. In this study, we introduced vanillin, a natural antioxidant that undergoes two redox reactions in succession. This enables it to inhibit the oxidation of Sn2+ or reduce Sn4+ back to Sn2+. As a result, it improves the efficiency of the solar cells and prolongs the open-air stability of Sn-based perovskite solar cells. By doping the perovskite material with 7.5% vanillin, we achieved an impressive efficiency of 13.18% using a flexible one-dimensional solar cell architecture, which currently represents the highest efficiency in Sn-based fiber-type perovskite solar cells. Additionally, exposer of the solar cells to 160W microwave irradiation for 3 minutes, caused the efficiency of the solar cell to recover from 88% to 96.5% (normalized efficiency) at 812 hours, and from 35.7% to 65.4% after approximately 2200 hours of aging under high relative humidity >75% and open-air conditions. This work demonstrates the potential of using natural antioxidants and short microwave irradiation as suitable approaches to increase the efficiency and prolong the lifetime of tin perovskite solar cells. | en_US |
| dcterms.abstract | In the third phase of this study, we demonstrated a novel and sustainable energy solution in the form of photovoltaic fabrics that can serve as reliable energy sources for wearable and mobile devices. The solar fabrics were woven using four fiber-type perovskite solar cells as the weft, and cotton yarns as the warp to create three types of weaves: plain, twill, and satin. The solar yarns in the weave repeats were connected in parallel and series configurations, and the output current and voltage were investigated. This approach of assembling fiber-type solar cells into solar fabrics achieves large surface area solar energy harvesting platforms with flexibility, three-dimensional deformability, and moisture and heat transfer characteristics of textiles. In this investigation, both the design and performance of the solar energy harvesting fabrics weaves were explored. The resultant fabric weaves were characterized under different solar connections and weave designs. The estimated area of the assembled weave repeats was 50 mm × 45 mm solar active area. With series connection of the inherent solar cells, the voltage increased gradually from 3.84V to 4.01V to 4.03V for plain, twill, and satin woven solar fabrics, respectively. Changing the solar cell connection to a parallel configuration caused a significant increase in current output from 3.877 mA/cm² to 3.902 mA/cm² to 3.916 mA/cm² for plain, twill, and satin solar fabrics. Maximum power density of 3.95 mW/cm² was registered with a satin solar fabric (area 22.5 cm²), with its inherent solar cells connected in a parallel configuration. | en_US |
| dcterms.extent | xvi, 136 pages : color illustrations | en_US |
| dcterms.isPartOf | PolyU Electronic Theses | en_US |
| dcterms.issued | 2025 | en_US |
| dcterms.educationalLevel | Ph.D. | en_US |
| dcterms.educationalLevel | All Doctorate | en_US |
| dcterms.accessRights | open access | en_US |
Copyright Undertaking
As a bona fide Library user, I declare that:
- I will abide by the rules and legal ordinances governing copyright regarding the use of the Database.
- I will use the Database for the purpose of my research or private study only and not for circulation or further reproduction or any other purpose.
- I agree to indemnify and hold the University harmless from and against any loss, damage, cost, liability or expenses arising from copyright infringement or unauthorized usage.
By downloading any item(s) listed above, you acknowledge that you have read and understood the copyright undertaking as stated above, and agree to be bound by all of its terms.
Please use this identifier to cite or link to this item:
https://theses.lib.polyu.edu.hk/handle/200/14096