由於積體電路的尺寸逐漸微縮，所以二維材料近年來受到許多研究團隊的關注。因為石墨烯具有可大面積成長、高載子遷移率以及高透光率等特色，使得他成為高速元件和光感測器中熱門的研究材料。而鋅在自然環境中的含量相當豐沛價格也較為便宜，因此氧化鋅透明導電薄膜也逐漸成為研究的目標。本論文將石墨烯與氧化鋅分別作為電晶體的基極端和射極端，並以矽基板作為集極端。由於單層的石墨烯與氧化鋅都很薄，因此可減少載子在基極中的複合機率以便提高電流增益，且可降低入射光被反射的機會。而石墨烯的特性與金屬相似，即便作為基極時使得基極很薄，也不必擔心電晶體會發生擊穿(punch through)現象，綜合以上概念本論文製作出一個在低偏壓的操作時具有高共射極電流增益(common-emitter current gain)的異質接面電晶體，並且具有不錯的電流與電壓響應度。

Because of the trend of size scaling in intergrated circuit, 2D material has received the attention of many research teams in recent years. Due to the edges on large-area production, high mobility and high optical transmittance, graphene has become a hit in the research field of the high-speed device and photodetector. On the other hand, transparent conducting thin film composed of Zinc oxide has gained lots of research momentum as well for its natural abundance in environment and low cost.
In this study, graphene and ZnO are served as Base and Emitter in the transistor, respectively, while the Si is served as Collector. For the extremely thin thickness in mono-layered graphene and ZnO, not only the probability of carrier recombination in Base can be decreased, which facilitates current gain, but also the reflection of the incident beam can be decreased. Regardless of the ultra thin Base, the metal-like characteristic of the graphene makes punch through effect barely happen. To sum up, we demonstrated a heterojunction transitor exhibiting high common-emitter current gain under the working condition of low bias voltage and remarkable current and voltage responsivity.

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