本篇論文研究金屬奈米粒子有機光電晶體（organic phototransistor, OPT）之元件光電特性。主要具體成果有四項: 第一，我們研究氧化鋁/聚甲基丙烯酸甲酯(PMMA)堆疊式絕緣層對有機電晶體漏電流的影響。和單層PMMA相比，堆疊式絕緣層除了可以有效地降低漏電流密度外，更可以進一步降低半導體的空乏電容。較低的空乏電容可歸因於較佳的並五苯的薄膜結晶，進一步提升有機薄膜電晶體的場效遷移率。第二，我們利用持續照光下電晶體的轉移特性曲線來探討金奈米粒子對光電晶體能量轉換效率的影響。在光照射下，含有金奈米粒子之有機光電晶體的汲極電流大幅度增加，且能量轉換明顯地從10.23%增加到18.03%。這結果說明可以透過金奈米粒子表面電漿共振的方式將光子能量聚集到半導體內，提升局部照光強度，進而增加能量的轉移效率。第三，展示金奈米粒子有效增強光電晶體在深紫外光光感測的能力。透過製程最佳化，可以精確地控制金奈米粒子在10nm以下。在240nm光波長照射下，無奈米粒子之光電晶體光響應為1.6 安培/瓦。而金奈米粒子之光電晶體，光響應可以提升至4.5 安培/瓦。第四、研究銀奈米粒子尺寸對有機光電晶體光響應度的影響。在白光照射下，當閘極電壓小於-20V，最大光響應度落在銀奈米粒子尺寸9-22奈米(2nm厚)。;In this thesis, we investigated the photodetection capability of organic phototransistors (OPTs) with metallic nanoparticles decoration. The main features encompass as follows. First, we investigated the effect of Al2O3/PMMA stack dielectrics on OTFT performance in terms of leakage and depletion capacitance. Compared to the OTFTs with single-layer PMMA, OTFTs with stacked-dielectrics exhibit better leakage-current blocking ability and a lower depletion capacitance thanks to better pentacene crystallinity. Secondly, we investigated the photo energy transfer efficiency enhancement by gold nanoparticles (Au NPs) for OPTs. We elucidated the transfer characteristics of OPTs without and with Au NPs layers under illuminationor not. Au NPs OPTs exhibit dramatic enhancement in drain current under illumination and significant increment in energy transfer efficiency accordingly. The energy transfers efficiency is 10.23 and 18.03% for OPTs with and without Au NPs, respectively. This result indicates that surface plasmon resonance greatly facilities the transfer of photon energy in semiconductor through the enhancement of localized light intensity. Thirdly, we have successful demonstrated that inclusion of Au NPs within Opts is conducive for deep UV detection. The size of Au NPs size is smaller than 10nm by precisely designed deposition process. The responsivity changes from 1.6 to 4.5 A/W when we included the Au NPs into OPTs. Fourthly, we investigated the effect of silver nanoparticles (Ag NPs) size on OPTs photo-detection. As the gate voltage is greater than -20 V, pentacene OTFTs with 2nm-thick Ag-NP decoration exhibited the highest responsivity.
