Graphitic Carbon Nitride-based Thin Films as New Functional Materials

石墨碳氮化物（GCN）是一种非常感兴趣的物质，因为它仅由碳和氮组成，并且对水的分解显示出高的光催化活性。到目前为止，GCN材料已经作为粉末获得并用于这些目的。如果GCN材料以薄膜形式存在，人们可以获得什么好处？如果聚乙炔只能以粉末形式存在，那么导电聚合物的科学和技术就不会出现，答案是明确的。虽然GCN薄膜具有许多优点，但对GCN薄膜的研究仍处于早期阶段。在2016年，我们的小组报告了可以通过气相沉积聚合获得自支撑GCN薄膜样品。GCN薄膜在水蒸气的存在下表现出驱动行为。为了通过掺入硼来调节GCN薄膜的能带隙，我们的小组已经开发了一种用于半导体的掺杂策略。然而，我们只获得了能带隙大于2.7 eV的材料，这是绝缘体。为了利用可见光或太阳光，需要具有较小能带隙的材料。在这里，我提出的碳杂化GCN（GCN-C）薄膜的合成通过两区化学气相沉积（CVD）方法。所得的GCN-C膜具有优异的机械性能、宽的光吸收、高的电导率和高的开/关比光电探测器，使其成为有前途的电子应用材料。这些发现代表了GCN薄膜作为电子材料领域的重大进展。

Graphitic carbon nitride (GCN) is a substance of great interest because it is composed only of carbon and nitrogen and shows a high photocatalytic activity for the splitting of water. So far, GCN materials have been obtained as powders and utilized for these purposes. If GCN materials are available in film form, what benefits one can obtain? The answer is clear considering that the science and technology of conductive polymers would not have emerged if polyacetylene was available only in the powdery form. Although films have many advantages, research on GCN films is still in the early stages. In 2016, our group reported that self-supporting GCN film samples could be obtained by vapor deposition polymerization. The GCN film showed actuation behaviors in the presence of water vapor. To tune the energy band gap of GCN films by incorporating boron, our group has developed a doping strategy for semiconductors. However, we only obtained materials with energy band gaps larger than 2.7 eV, which are insulators. To utilize visible light or sunlight, a material with a smaller energy band gap is necessary. Here I present the synthesis of carbon hybridized GCN (GCN-C) films via a two-zone chemical vapor deposition (CVD) method. The resulting GCN-C films exhibit outstanding mechanical properties, broad optical absorption, high electrical conductivity, and high on/off ratio photodetectors, making them promising materials for electronic applications. These findings represent a significant advancement in the field of GCN thin films as electronic materials.