| 摘要: | 隨著技術的迅速進步席捲世界，共創美好未來，人類友善的技術方法至關重要。
研究人員一直在適用於醫學、研究、防禦系統、太空技術，以及顯示器等領域的設備
物理和製造領域進行深入研究。其中谷歌眼鏡、電子腕帶、以及醫療設備引領了趨勢
發生了變化。至今，透明、可拉伸且重量極輕的奈米設備取代了傳統的配件，使其舒
適地放置在人體皮膚上，它們可以在較低的工作功率下運作。二維混合系統是研究人
員開發透明且可拉伸的能夠進行光感測器和隨機雷射元件的混合設備的最佳選擇。鑭
系元素摻雜的上轉換奈米粒子表現出反斯托克斯現象，由於這種現象，當被較低能的
光子激發時，它們會發出較高能的光子。鑭系元素由多能態系統組成，該系統為非線
性過程打開了道路，例如：激發態吸收、能量躍遷上轉換過程，以及光子雪崩等。鑭
系元素之4fn 電子結構產生的多能態導致更長的激發時間光生載流子的能態壽命。這為
二維混合系統（例如混合上轉換奈米粒子/石墨烯）中的高靈敏度光電檢測系統領引了
道路。多能態系統還提供了適用於居量反轉之不同亞穩態，從而開闢了利用上轉換奈
米粒子製造雷射器件之新途徑。
設計、製作及研究目的：
1. 整合上轉換奈米粒子及以石墨烯為基底之透明、可穿戴式、寬能帶及高度敏感之光
電探測器。
2. 具有高度敏感、可見盲、可穿戴式及全向之近紅外光電探測器。
3. 具有可拉伸及生物應用的自給自足和高效率之金與上轉換奈米粒子之複合雷射器件。
4. 可用於光學檢測和隨機雷射之阿基米德螺旋波紋微結構。
本論文成功地製造了由上轉換奈米粒子和石墨烯組成的二維混合系統。從包括具有
不同功能的上轉換奈米粒子的可拉伸光電探測器中觀察到了高靈敏度的寬帶和可見盲
窄帶之光電探測器。在連續波長980 奈米雷射光源照射之下，從夾在金奈米顆粒之間
可觀察到超低閾值之隨機雷射現象；當經歷可拉伸的微結構（如波紋結構和阿基米德
螺旋波紋微結構）時，亦觀察到上轉換奈米粒子之隨機雷射現象。這些具有新穎設計
之器件為可拉伸和人類友好型之光電設備領域，提供了正在進行的研究做出了重大貢
獻。;With the rapid technological advancements engulfing the world for better future, human friendly technological approach is all that counts. Researchers have been carrying out intense research in the fields of device physics and fabrications suitable for the fields of medicine, research, defense systems, space technologies, displays, etc. A shift in the trends is observed where google glass, electronic wrist bands, medical accessories, etc. are now overtaken by transparent, stretchable, and extremely light weight nanodevices capable of working under lower operating powers when placed conformably on human skin. Two-dimensional (2D) hybrid systems are the best choice for researchers when it comes to working towards developing transparent and stretchable hybrid devices capable of photodetection and random lasing. Lanthanides doped upconversion nanoparticles exhibit antistokes phenomenon owing to which when excited by lower energy photons, these emit photons of higher energies. The lanthanides comprises of a multi-energy level system that opens way for non-linear processes such as excited state absorption, energy transfer upconversion process, photon avalanche, etc. The multi-energy sublevels from the 4fn electronic configuration of lanthanides results in longer excited state lifetime for photogenerated charge carriers. This paves way for highly sensitive photodetection in 2D hybrid systems (e.g. upconversion nanoparticles/graphene hybrid). The multi-energy level system also provides for different metastable states suitable for the state of population inversion thus opening new ventures for fabricating lasing devices using upconversion nanoparticles. Research aims: 1. To design, fabricate and study transparent, wearable, broadband, and highly sensitive upconversion nanoparticles and graphene-based hybrid photodetectors. 2. To design, fabricate and study highly sensitive, visible blind, wearable, and omnidirectional near-infrared photodetectors.
3. To design, fabricate and study self-sufficient and highly efficient gold sandwich
upconversion nanocomposites lasers for stretchable and bio applications.
4. To design, fabricate and study Archimedean spiral rippled microstructures for
photodetection and random lasing.
The 2D hybrid systems comprising of upconversion nanoparticles and graphene were
successfully fabricated. Highly sensitive broadband and visible-blind narrow band
photodetection was observed from stretchable photodetectors comprising of upconversion
nanoparticles with different functionalities. Ultra-low thresholds random lasing action was
observed from upconversion nanoparticles sandwiched between gold nanoparticles upon
continuous wave 980 nm laser pumping. Random lasing actions were also observed from
upconversion nanoparticles when subjected to stretchable microstructures such as rippled
structures and the Archimedean spiral rippled microstructures. These devices with novel
designs make a significant contribution to the ongoing research in the field of stretchable and
human friendly optoelectronic devices. |
