石墨烯與矽之蕭基接面應用於光陰極水分解產氫研究

Abstract

石墨烯是由六角型格子狀的碳原子所組成的單層二維材料，因特殊的能帶結構與原子排列，讓它有著許多優異的特性，例如可調變的功函數、高穿透度、高載子遷移率、易被化學修飾等，這些性質使得石墨烯大量應用於光電元件領域中，而近幾年再生能源的重要性日益漸增，我們除了可以利用矽基板與石墨烯的結合製作出太陽能電池發電外，也可以將它應用於電化學能源領域中。 本文將研究利用石墨烯與矽形成的蕭基接面來增加水分解產氫效率。首先，我們利用高分子EVA 進行石墨烯轉印，使其能夠伏貼於金字塔狀的抗反射矽基板上，可從PEC 效率量測圖中發現，其飽和電流值與起始電位有著顯著地提升。之後，我們利用此蕭基接面進行光沉積反應，讓奈米鉑粒子修飾於石墨烯表面，而這些奈米金屬粒子具有催化作用，使水分解反應更容易發生，並且表現在起始電位上。

Graphene,a two-dimensional material, is a single-atom thick sheet of carbon atomsarranged in a 2D network of ring structures (a honeycomb lattice). graphene has a lot of promising properties such as high transparency, high thermal conductivity, high carrier mobility, tunable work function, and hence graphene has been considered as an outstanding candidate electrode material for Schottky junction solar cell .Besides,hydrogen energy has gained attention as the next generation form of clean energy, therefore we want to utilize graphene/silicon Schottky junction as a device of hydrogen production for photoelectrochemical (PEC) water splitting. In the first part of this thesis, we successfully transferred EVA/graphene noto antireflective silicon surfaces for forming a Schottky junction for PEC water splitting .Because of silicon nanostructures, the device reaches a high photocurrent density of 43 mA/cm2. In the second part, we use graphene/silicon Schottky junction to decor-ate the graphene sheet with Pt particles through photo-deposition method.On account of Pt catalysts, the optimized device has significant anodic shift of onset. In the final part, We study about photo-deposition in 2D material for understanding charge transfer in graphene-silicon Schottky junction and MoS2/WSe2 heterojunction.