半導體奈米複合物之多功能光電元件

本論文的研究旨在研發與電子皮膚兼容的高性能、多功能光電元件。其元件具備了物聯網應用所需的特性。本研究取得了一些突破，這些發現的重點如下。 1. 藉由顏色感知壓力：結合高靈敏度壓力感測器與多波長發光二極體的整合式元件我們展示了一種高靈敏度、低成本且不損害環境的壓力感測器。本研究使用的壓力感測器使用嵌入了奈米銀線的羊毛纖維，壓力感測器具有高靈敏度、寬廣的壓力感應範圍、易於製造且重量輕。使其可用於便攜式和可穿戴設備。藉由與具有多波長發射的發光二極體整合，我們展示了具備多功能且發光二極體整合壓力感測器，該感測器能夠將不同的施加壓力轉換為具有不同波長的發光。由於壓力傳感器的高靈敏度，我們甚至使用節拍器和擴音器來演示聲音信號檢測與光傳輸。該多功能壓力感測器的技術可以被應用在智慧照明，醫療健康，可見光通訊和其他物聯網等應用。 2. 由光閘效應、壓電效應和鐵電效應驅動的超高性能自供電可撓光偵檢器由於物聯網在實際應用時需要動態性、即時性、即地性進行數據收集，因此在超靈敏感測網絡中採用可自供電、可撓、輕巧的元件已成為未來感測器系統的一個重要議題。在這篇研究中，使用聚（偏二氟乙烯-三氟乙烯共聚物）的鐵電薄膜，通過光閘效應、壓電效應和鐵電效應的結合，實現了一種新型的高性能自供電光偵檢器。在合理的元件設計下，藉由光照射，外部應變或電壓極化偶極而產生的內部電場，可以調變界面處的載流子傳輸行為。這使光電流和元件的性能得以顯著提升。這項研究中提出的前所未有的光偵檢器具有許多優點，包括機械可撓性和輕巧性，使其能夠式用在任意表面形貌；此外，其自供電能力和高可靠性為下一代光電元件開發迫切需要的性質。此人性化界面元件可被應用在惡劣環境中的可穿戴式無線通信。 3. 可自供電，自我修復和可改變型態的紫外光偵檢器近年來，自我修復元件的出現引起了學術界和業界的極大關注。自修復的元件可以在發生意外破壞時自動恢復破裂面，從而可以有效地延長元件的使用壽命，進而提高元件耐用性並降低更換成本。因此，結合可穿戴與自我修復性質的電子元件的已經成為智慧穿戴元件中不可或缺的特性。在這篇研究中，我們提出了第一個利用瓊脂糖/聚乙烯雙網狀結構水凝膠為基板的自供電、自修復和可穿戴的紫外光偵檢器；該偵檢器具有良好的優勢機械強度、自我修復能力和多重損害的耐受性。藉由雙網狀結構水凝膠，光偵檢器在五個修復週期後能夠恢復90％的初始效率，且其修復時間都僅有10秒鐘。該元件展現多種優勢，包括所有元件製程皆是使用噴塗法、自供電、生物相容性、良好的靈敏度、機械可撓性和出色的可修復性，這些都是構建智慧電子元件系統的重要條件。此自我修復光偵檢器擴展了電子皮膚的未來設計方向，也為開發下一代可穿戴式電子產品提供了新平台。 4. 同調福斯特共振能量轉移：電激發無共振腔量子點雷射由於無共振腔雷射的獨特優勢，包括高發光強度、廣角雷射性質和簡單的製程方式，吸引了許多團隊共同研究發展。其研究方向集中在嘗試突破光激發無共振腔雷射進展到電激發無共振腔雷射。然而，目前的進展仍受限於散射過程中光子的高損耗和低增益，使得雷射不易形成。在這篇研究中，我們提出了一種新的機制名為同調福斯特共振能量轉移實現電機發無共振腔量子點雷射。在同調福斯特共振能量轉移機制中，當光在混合量子點中多次散射而形成同調封閉光路徑時，施體量子點不僅當作散射中心；還能利用調福斯特共振能量轉移機制轉移能量給受體量子點。因此，雷射可以容易地形成且雷射的臨界值可有效被降低。本研究提出產生電激發無共振腔雷射的方式可被延伸至其他量子點系統。這是邁向全光譜無共振腔雷射的重要一步，應用層面從生醫診斷到光通訊都可適用。

關鍵字

電子皮膚；壓力感測器；壓電光電子效應；自修復；無共振腔雷射

並列摘要

Research of this dissertation aims to high performance, multi-functional optoelectronic devices that are compatible with electronic skin. These devices feature the essential characteristics required for IoT applications. Several breakthroughs have been achieved and highlights of these discoveries are accordingly illustrated as follows. 1. Seeing Pressure in Color: An integration of highly-sensitive pressure sensor and light emitting diode with multi-wavelength emission We demonstrate a highly sensitive, low-cost, environmental friendly derived from wool-based pressure sensor with wide pressure sensing range using wool bricks embedded with a Ag nano-wires. The easy-fabrication and light weight allow portable and wearable device applications. By integration with a light emitting diode possessing multi-wavelength emission, we illustrate a hybrid multi-functional LED-integrated pressure sensor that is able to convert different applied pressures to light emission with different wavelengths. Due to the high sensitivity of the pressure sensor, the demonstration of acoustic signal detection has also been presented using sound of a metronome and a speaker playing a song. This multi-functional pressure sensor can be implemented to technologies such as smart lighting, health care, visible light communication (VLC), and other internet of things (IoT) applications. 2. Ultrahigh- Performance Self-Powered Flexible Photodetector Driven from Photogating, Piezo-phototronic, and Ferroelectric Effects Owing to the need for dynamic, real-time, and on-site data collection in internet of things (IoT) applications, the realization of ultra-sensitive sensing networks with self-powered, flexible, and lightweight devices has become an important issue for the development of sensor systems. In this work, a novel, high-performance, self-powered photodetector is achieved through the combination of photogating, piezo-phototronic and ferroelectric effect by incorporating a ferroelectric thin film of poly (vinylidene fluoride-co-trifluoroethylene) (PVDF-TrFE) in a rationally designed device structure with suitable band alignment, which can modulate carrier transport behavior at the interface due to the internal electric field produced by light illumination, external strain or voltage-poled dipole. This enables photocurrent and overall device performance to improve significantly. The unprecedented photodetector presented in this study has several merits, including mechanical flexibility and light weight, that allow it to adapt to arbitrary surface topology; additionally, its self-powering capability and high reliability are urgently needed for the demanding functionality of devices for the development of next-generation optoelectronic devices, spanning from wearable communication to unattended harsh environments with a human-friendly interface. 3. Self-powered, Self-healed and Shape-adaptive Ultraviolet Photodetectors Emerging of self-healed devices in these years has drawn great attention in both academics and industries. Self-healed devices can autonomically restore the rupture as unexpected destruction occurs, which can efficiently prolong the lifespan of the devices, hence an enhanced durability and decreased replacement cost. As a result, integration of wearable devices with self-healed electronics has become an indispensable issue in smart wearable devices. In this work, we present the first self-powered, self-healed and wearable ultraviolet (UV) photodetector based on the integration of agarose/poly(vinyl alcohol) (PVA) double network (DN) hydrogels, which owns the advantages of good mechanical strength, self-healing ability, and tolerability of multiple damages. With the integration of DN hydrogel substrate, the photodetector enables 90% of initial efficiency to be restored after five healing cycles, and each rapid healing time is suppressed to only 10s. The proposed device has several merits, including all spray coating, self-sustainable, biocompatible, good sensitivity, mechanical flexibility, and outstanding healibility, which altogether are essential to build smart electronic systems. The unprecedented self-healed photodetector expands the future scope of electronic skin design, and also offers a new platform for development of next-generation wearable electronics. 4. Coherent Förster Resonance Energy Transfer: A New Paradigm for Electrically-Driven Cavity-Free Quantum Dots Laser Owning to the distinct advantages of cavity-free lasers including high spectral intensity, broad angle emission, and simple fabrication process through a great collaborative effort around the world, the present development for cavity-free lasers has been focused on a breakthrough from optical pumping to electrical pumping. However, progress is rather limited due to high optical loss and low gain. In this work, we demonstrate the first electrically-pumped cavity-free quantum dots (QDs) laser with visible emission based on a new paradigm named coherent Förster resonance energy transfer (CFRET). In the CFRET process, when a coherent closed loop is formed due to multiple scattering of the emitted light traveling in mixed donor and acceptor QDs, the donor QDs not only serve as scattering centers, but are also enabled to transfer energy to acceptor QDs coherently. The laser action can be easily achieved and the lasing threshold is greatly reduced. Our approach of electrically-pumped QD-based cavity-free lasers is quite general, and it can be extended to many other QDs systems. This represents a remarkable step toward to a full-spectrum cavity-free laser for practical applications, spanning from biomedical diagnosis to light communication.