加馬射線對有機薄膜材料、導電聚合物和功能材料的影響: 藉由同步輻射研究其結構和電特性

Influence of gamma ray irradiation on organic films, conducting polymers and functional materials: its effects on structural and electronic properties studied by synchrotron radiations

阿什温(Anbalagan, Aswin kumar)

指導教授 ： 李志浩

國立清華大學/原子科學院/工程與系統科學系/博士(2020年)

摘要

這篇論文主要在研究利用同步輻射分析60Co gamma輻射對高遷移率有機材料、聚合物導電材料和功能材料的結構、電子和電機性質的影響。首先，使用有機膜並五苯熱沉積在矽基板(001)平面上後施予3 kGy的異向性gamma輻射，曝露到平面和平面法線方向gamma輻射的並五苯結構依舊維持堅固。藉由簡單的電阻器設計量測電阻可進一步確認，曝露到平面方向(π-π鍵方向)gamma輻射的並五苯其導電度會增加，該現象反映出電荷載子的轉移，與X射線吸收光譜的結果一致，皆表明電荷載子濃度增加。然而，曝露到gamma輻射的影響使得並五苯的缺陷增加，導致電荷載子遷移率降低。其次，由於PEDOT:PSS的廣泛應用及高導電性，研究方向朝向gamma輻射對PEDOT:PSS的結構和電性質的影響，利用不同輻射環境(大氣和真空下)使PEDOT:PSS的缺陷和自由基產生進而改變結構和電性質。由電子自旋共振(ESR) 光譜表明，在真空環境下照射輻射會產生尖銳的強峰，該峰是由於電荷離域和聚合物結構取向的變化產生。最後，研究gamma射線對氧化鋅塗層棉織物基功能材料的影響，與沒曝露輻射的樣品相比，光催化自清潔和可洗性研究也證實了，曝露輻射的樣品具有更好的性能和更強的鍵結。這項研究描述受輻射照射後的氧化鋅奈米粒子和棉織物間增強鍵結的方法，此方法可被用於紡織工業的替代途徑。

關鍵字

半導體 ； 有機材料 ； 薄膜 ； 加馬射線 ； 電性能

並列摘要

This thesis work mainly focus on the study of 60Co gamma irradiation effects on structural, electrical and electronic properties of high mobility organic materials, conducting polymers and functional materials by using synchrotron radiations. At first, thermally deposited pentacene based organic films on Si (001) substrates are studied after gamma irradiation upto 3 kGy anisotropically. Pentacene films structure remains robust after gamma ray exposure upto 3 kGy along both plane normal and in-plane directions. Resistance measurement by using simple resistor design further confirmed the increase in conductivity of the irradiated samples along in-plane direction (- direction), which is responsible for the carrier transport. These results are consistent with the X-ray absorption spectroscopy (XAS) results that manifests the increase in carrier concentration. However, the mobility of the samples gets decreased due to the defects created in the sample. Secondly, the research focused on the gamma irradiation effects on PEDOT: PSS due to its versatile applications and highly conducting properties. PEDOT: PSS samples are studied at different irradiation environment (i.e. air and vacuum) to understand the change in structural and electronic properties due to the defects and radicals created in the samples. Electron spin resonance spectra revealed that irradiating at vacuum environment leads to the sharp intense peak which arises due to the changes in the charge delocalization and orientation of the polymer structure. At last, gamma irradiation effects on zinc oxide (ZnO) coated cotton fabrics based functional materials are presented. Photocatalytic self-cleaning and washability studies also confirmed the better performance and binding of irradiated ZnO coated fabrics in comparison to the pristine one. This work described a way to enhance the binding between ZnO nanoparticles with cotton fabrics after irradiation which could be exploited as an alternative route in textile industries.

並列關鍵字

semiconductor ； organicmaterial ； thinfilms ； gammairradiation ； electricalproperties

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