臺灣大學: 化學工程學研究所林祥泰詹令晨Chan, Ling-ChenLing-ChenChan2013-03-272018-06-282013-03-272018-06-282012http://ntur.lib.ntu.edu.tw//handle/246246/252142電阻式記憶體元件是一種採用電極/反應層(有機高分子)/電極的三明治式夾層結構的記憶體元件。在這篇論文中,我們建造了一個理論模型可以用來描述電阻式記憶體元件的電流電壓特性曲線。我們發現當給體-受體有機高分子在電場的影響下由基態變成激發態時,其分子結構會改變,此時激發態的最高佔有分子軌域會提高,最高佔有分子軌域由基態提高到激發態的能量差是我們要注意的性質。最高分子軌域的提高會使得反應層和電極間的電洞注入能障降低,因而使得電流由低導電曲線提高到高導電曲線。 我們利用基態和激發態的最高佔有分子軌域及最低未佔分子軌域分別來模擬得到和實驗結果相當吻合的低導電曲線和高導電曲線。除此之外,我們還可以由此模擬得到合理的高導電態和低導電態的電流比。由研究中可看出高導電態和低導電態的電流比和最高佔有分子軌域的能量差有著良好的線性關係,所以我們可以經由記算得到的最高佔有分子軌域的能量差來預測一個給體-受體有機高分子材料的高導電態和低導電態的電流比。In this article, we established a theoretical model that can describe the voltage-current characteristics of resistive memory devices, containing a layer of the organic polymer semiconductor material sandwiched between two electrodes. We found that the rise of HOMO level of Donor-Acceptor polyimides due to the structure change from ground state to excited state reduces the hole injection barrier between cathode and polymer, leading to the enhancement of the electric current. In other words, the applied external field stimulates the polymer to the switch from OFF state to ON state. We can simulate the I-V curves in excellent agreement with the experiment results by using electrical property of ground state and excited state for simulating the low conductivity curve and high conductivity curve, respectively. Furthermore, we can obtain a reasonable ON/OFF ratio by simulation. The logarithm of ON/OFF ratio and △HOMO exhibit a linear correlation. Therefore, the ON/OFF ratio of new polyimide materials can be predicted by calculating the change in the HOMO level between the ground and excited states.140 bytestext/htmlen-US電阻式記憶元件高分子含時密度泛含理論電流比RRAMpolyimideTDDFTON/OFF ratiothesishttp://ntur.lib.ntu.edu.tw/bitstream/246246/252142/1/index.html