非揮發記憶體用之高分子/核殼奈米顆粒奈米複合材料之合成與元件製備

Abstract

本計畫主要目地在發展(i)非揮發記憶體用之共軛高分子/奈米顆粒與塊狀高分子奈米複合材料之合成與製備、(ii)製備光寫入與電抹除記憶體電晶體、(iii)製作有機場效電晶體類型記憶體電寫入與電抹除。將合成數個可應用於有機記憶體之有機高分子材料，這些有機高分子材料包含(i)具有高吸光係數之高分子、(ii)具有高結晶性之高分子、(iii)同時具有電子施體與電子受體單體之高分子。另外地，以高分子混合含有核殼結構之金屬/絕緣層與塊狀高分子包覆金屬奈米粒子為目標；我們將分別以含有核殼結構之金屬/絕緣層、銀與鉑之奈米粒子為目標產物，預期在摻入這些奈米粒子於高分子基材內形成複合材料後，能增加誘導轉移電子於奈米顆粒中的滯留時間與抓取能力，進而增加元件的記憶時間。此外，亦將對所合成之金屬奈米粒子的表面進行改質，使奈米粒子表面能與高分子之側鏈端產生鍵結，以期能控制奈米粒子摻雜於高分子基材中之分散性與均勻度。將會製作三明治結構與場效電晶體類型之電子記憶體元件，我們將分析各種不同複合材料及條件下的材料及元件性質，經由變溫量測以期望了解無機-有機複合材料複雜系統之電荷補捉及儲存機制。我們將使用導電式原子力顯微鏡在真空的環境下，利用電流影像穿遂圖譜量測法且透過變溫電流電壓量測方法來探討電子於複合材料中於奈米尺度下的傳導機制，探討無機-有機複合材料的存儲密度，同時也可以了解高分子薄膜的表面形態和傳導性質的相關性，進而建立少數/單一奈米粒子儲存機制的模型。

The objectives of this study are (i) to develop conjugated polymer/ core-shell and diblock copolymer nanocomposite for fabricating non-volatile memory devices, (ii) to prepare optical-programming and electric-erasing memory-transistor devices and (iii) to fabricate organic effect transistor type memory. The conjugated polymer including (i) high absorbency index, (ii) high crystallinity, (iii) electron-donor and electron-acceptor moiety will be synthesized. In addition, the goal will blends core-shell nanoparticles into conjucated polymers and incorprates metal nanoparticles into diblock copolymers. We will employ core-shell, silver and plantium nanoparticle for target products and improving the electron retention time of the nanoparticles, thereby enhancing the life time of the memory device and trapping abilities. Furthermore, the surface ligands on these nanoparticles will be tailored to the side-chain-tethered functional groups of the polythiophene in such a way that weak bondings will be presented between them. In this way, these nanoparticles will be able to be dispersed homogeneoudy in the conjugated polymer matrix, thereby creating consistant morphology in the nanocomposites and minimizing variations introduced by solution processing techniques. We will analyze the reliability and the transport mechanism of the memory devices built from polymer/nanoparticle using variable temperature probe station in a high vacuum environment. The uniqueness of the bistable memory behavior in nanoscale, the transport mechanism in the high and low impedance status will be investigated. Conductive atomic force microscopy will be adopted to characterize the organic-inorganic nanocomposites material properties in the nanoscale. Current imaging tunneling spectroscopy (CITS) allows us to probe the local electronic properties of the hybrid organic-inorganic thin film as a function of the electric stress, and simultaneously correlate to the material topography. We could systematically investigate the relationship between morphology and electric properties. This technique also can be used to read and to write hybrid organic-inorganic thin film with a size as low as 20 nm. Devices with few or single gold nanoparticles in nanocomposite system and related model will be constructed to elucidate the structure, morphology and performance of the devices.