高分子複合材輔助水熱法成長雙軸向規則排列氧化鋅晶體薄膜

The study of the hydrothermal growth of biaxially oriented ZnO layers through the assistance of polymer composite

顏士喬(Shih-Chiao Yen)

指導教授 ： 陳厚光

義守大學/理工學院/材料科學與工程學系/碩士(2017年)

摘要

本實驗將使用高分子複合材後輔助水熱法後進行雙軸向(biaxial)規則排列氧化鋅晶體薄膜成長。實驗主要分兩大部分，ZnO晶柱/PMMA複合材側向成長跟圖案化ZnO /PMMA複合材側向成長。ZnO晶柱/PMMA複合材側向磊晶成長是於a-plane藍寶石基板上成長高準直磊晶氧化鋅柱，再使用氧化鋅磊晶柱轉移到PMMA高分子基地中獲得到氧化鋅高分子複合材。由於氧化鋅磊晶柱可完全轉移至PMMA基板上且仍保有高度in-plane規則方向性排列，再以此為基礎進行水熱法成長，在水溶液中添加檸檬酸鈉進行促使氧化鋅側向成長速率提高，以達到在高分子複合材上生長完全癒合薄膜之目的。
圖案化ZnO /PMMA複合材側向磊晶成長則是利用光蝕刻微影技術製作圖案化緩衝ZnAl2O4，利用水熱法ZnO成長對ZnAl2O4及Al2O3基板之間選擇性的差異，製備圖案化ZnO陣列，之後轉移至PMMA高分子基板製成規則圖案排列ZnO /PMMA複合材，再透過水熱法進行雙軸向側向成長癒合成連續薄膜。其中主要採用圖案有六角形點陣列、蜂巢狀陣列及改良型六角形點陣列。其中發現在三種圖案結構所製成PMMA複合材基板上以水熱法進行側向成長皆可以獲得完全癒合且具有雙軸向方向規則排列。其中在六角形點陣列圖案化ZnO /PMMA複合材上進行側向成長膜層癒合狀況良好且平整並有較佳晶體品質。在本研究中，將探討在不同氧化鋅陣列結構所製成PMMA複材上進行氧化鋅側向成長對於膜層中顯微結構及光學性質、X光繞射及光譜的影響。

關鍵字

氧化鋅 ； 高分子複合材 ； 側向磊晶

並列摘要

In this study, the hydrothermal growth of ZnO films with biaxial alignment were implemented by the assistance of ZnO/polymer composite templates. This thesis can be divided into two parts: (1) ZnO microrods/polymer composites promote biaxially oriented growth of ZnO films; (2) patterned ZnO/polymer composites promote biaxially oriented growth of ZnO films.
For preparation of ZnO microrods/polymer composite, we infiltrated polymethyl methacrylate (PMMA) into epitaxial ZnO microrod arrays on sapphire substrates. After curing, the resulting ZnO/polymer composite layers were transferred to PMMA sheets by combining solvent-bonding and peel-off processing. It was evident that the ZnO microrods embedded in the polymer matrix retained in-plane alignment of ZnO microrods originally grown on sapphire substrates. The hydrothermal growth of ZnO were performed on the opposite face of ZnO microrods/polymer composite. To obtain full coalesced ZnO layer, the addition of sodium citrate into growth solution let to promote the growth of ZnO in lateral directions. Eventually, the biaxially oriented ZnO layer can be grown on the composite templates.
For patterned ZnO/ polymer composites promote biaxially oriented growth of ZnO films, patterned epitaxial ZnAl2O4 buffer layers were fabricated on sapphire substrates by combining lift-off and solid state reaction processing. Three kinds of pattern designs, hexagonal array, honeycomb, and modified hexagonal array, were employed to fabricate pattern buffer layers, respectively. Site-controlled growth of patterned ZnO structures on the patterned buffer layers was realized by low-temperature hydrothermal processing. The three kinds of patterned ZnO structures can be transferred onto PMMA sheet by combining solvent-bonding and peel-off processing to prepare patterned ZnO/PMMA composite templates. The fully coalesced growth of biaxially oriented ZnO layers on the three kinds of patterned ZnO/polymer composite was evident. The coalesced ZnO layer grown on the patterned ZnO/PMMA composite with conventional hexagonal array exhibited flat and better crystalline quality. In this study, the microstructures and optical properties of coalesced ZnO layers grown on patterned ZnO/PMMA composite templates with various pattern designs were investigated by x-ray diffraction and photoluminescence measurement.

並列關鍵字

ZnO ； polymer composite ； lateral epitaxial

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