| 摘要: | 有機/無機複合式垂直發光電晶體（Organic/Inorganic Integrated Vertical Light-Emitting Transistor, VLET）因其具備高度微型化潛力與整合發光與開關功能的優勢，已成為新世代光電元件的研究重點。然而，目前對其內部微觀載子傳輸與發光機制仍缺乏深入探討。本論文採用Silvaco公司提供之科技電腦輔助設計軟體（Technology Computer-Aided Design, TCAD），結合實驗驗證與模擬分析，系統性探討複合式VLET元件內部的載子行為與電流分布特性。
首先建構ZnO橫向及垂直電晶體、Super Yellow單載子二極體、有機發光二極體與複合式發光二極體來驗證各種材料參數與使用之物理模型的合理性。並確保模擬與實驗結果的高度擬合。最後利用在不同元件中得出的材料參數來建立並模擬複合式垂直發光電晶體中的電流分布等微觀物理行為。
本研究的結尾深入探討VLET中ZnO/SY的界面電子能障、載子遷移率及源極電極的設計對元件表現的影響。受限於程式本身的模組設定，我們將VLET的發光功率與標準的複合式發光二極體類比。
研究結果顯示，兩層材料間的電子注入能障大幅影響元件的發光功率但對其電流影響甚微。並且實驗中觀察到大面積均勻發光的原因來自於無機材料的高遷移率，當無機材料的遷移率降低時，在VLET中的等效通道深度縮短，並且總電流也會隨之下降。而在對應的OLED中也會觀察到功率下降的現象。
在有機材料中的主要載子（電洞）遷移率提升時，在VLET中會觀察到電流會往絕緣層側壁集中，雖然會使元件的電流提升，但會降低其等效通道深度使得電流的均勻性下降。並且在對應的OLED元件中也可以同時觀察到電流與功率的增長，但對整體的量子效率影響甚微。最後在不同的源極設計中，使元件的開口率變化，在VLET中觀察到在兩層材料間的電位會重新分布且更加均勻，使得電流提升到與對應的OLED相當。
本研究成功的整合Silvaco TCAD工具模擬出有機/無機複合式垂直發光電晶體，歸納出實驗上觀察到的大面積均勻發光的原因。並且提出了各種優化VLET的辦法，本研究成果將對未來高效能、微型化元件設計提供重要理論基礎與參數指引。
;Organic/Inorganic Integrated Vertical Light-Emitting Transistors (VLETs) have emerged as a promising candidate for next-generation optoelectronic devices due to their high potential for miniaturization and the integration of light emission and switching functions. However, the internal mechanisms governing carrier transport and light emission in such devices remain insufficiently explored. In this study, Technology Computer-Aided Design (TCAD) software provided by Silvaco was employed to systematically investigate the carrier dynamics and current distribution characteristics within composite VLET structures through combined experimental validation and simulation analysis.
To establish the simulation framework, we sequentially constructed and verified the validity of physical models and material parameters using ZnO-based lateral and vertical transistors, Super Yellow single-carrier diodes, organic light-emitting diodes (OLEDs), and hybrid light-emitting diodes. The extracted parameters were then applied to simulate microscopic current behaviors within the VLET.
In the final stage, we explored the effects of the ZnO/Super Yellow (SY) interface energy barrier, carrier mobility, and source electrode design on device performance. Due to the limitations of the simulation module, the output power of the VLET was compared against that of a standard hybrid OLED. The results revealed that the electron injection barrier at the ZnO/SY interface significantly influences light-emission power while having minimal impact on current. Additionally, the observed large-area uniform emission in experiments is attributed to the high mobility of the inorganic layer. When this mobility is reduced, the effective channel depth in the VLET shortens, and the overall current decreases, leading to a corresponding drop in power output in the OLED.
Enhancing hole mobility in the organic layer led to current crowding near the insulating sidewall in the VLET, which increases overall current but reduces current uniformity. Corresponding OLEDs also exhibited increased current and output power, though with negligible impact on quantum efficiency. Finally, variations in the source electrode’s opening area altered the potential distribution across the ZnO/SY interface, improving current uniformity and raising the VLET current to levels comparable to OLEDs.
This study successfully implemented a comprehensive VLET simulation using Silvaco TCAD tools and elucidated the mechanism behind experimentally observed uniform emission. Several optimization strategies were proposed, and the findings provide valuable theoretical foundations and design guidelines for future high-performance, miniaturized optoelectronic devices. |
