valence band

简明释义

价带

英英释义

例句

1.In insulators, the valence band (价带) is fully occupied, preventing electrical conduction.

在绝缘体中，价带是完全占据的，从而阻止电导。

2.When light is absorbed, electrons can be excited from the valence band (价带) to the conduction band.

当光被吸收时，电子可以从价带激发到导带。

3.In semiconductors, electrons in the valence band (价带) are responsible for bonding between atoms.

在半导体中，价带中的电子负责原子之间的结合。

4.The properties of a material can change significantly if the valence band (价带) is altered.

如果改变价带，材料的性质可能会发生显著变化。

5.The energy gap between the valence band (价带) and the conduction band determines a material's electrical conductivity.

在价带和导带之间的能量间隙决定了材料的电导率。

作文

The concept of the valence band is fundamental in the study of solid-state physics and materials science. Understanding this term requires a grasp of how electrons are arranged within an atom and how they interact in a solid material. The valence band, specifically, refers to the energy band that contains the outermost electrons of an atom, which are involved in chemical bonding and electrical conductivity. These electrons are crucial because they determine the electrical properties of materials, including whether a substance is a conductor, semiconductor, or insulator.To elaborate, in a solid, atoms are closely packed together, and their outer electrons overlap with those of neighboring atoms. This overlapping leads to the formation of energy bands, where the valence band is filled with electrons while the next higher energy band, known as the conduction band, may be partially filled or empty. The gap between these two bands is called the band gap, and it plays a critical role in determining a material's electrical characteristics.In conductors, the valence band and conduction band overlap, allowing electrons to move freely and conduct electricity. In semiconductors, the band gap is small enough that thermal energy can excite some electrons from the valence band into the conduction band, enabling limited conductivity. Insulators, on the other hand, have a large band gap, meaning that electrons in the valence band cannot easily jump to the conduction band, resulting in poor conductivity.The understanding of the valence band is not only essential for theoretical physics but also for practical applications in technology. For instance, the development of semiconductor devices, such as transistors and diodes, relies heavily on manipulating the properties of the valence band. Engineers and scientists can modify the electronic properties of materials by introducing impurities, a process known as doping. By adding certain elements, they can create n-type or p-type semiconductors, which have different charge carrier concentrations and are essential for creating efficient electronic devices.Moreover, advancements in nanotechnology and materials science have led to the exploration of new materials with unique valence band properties. Graphene, for example, exhibits remarkable electrical conductivity due to its unique band structure, where the valence band and conduction band touch at certain points, allowing electrons to move with minimal resistance. Similarly, research into topological insulators has revealed materials that have insulating properties in their bulk state but conductive states on their surfaces, again linked to the behavior of the valence band.In conclusion, the valence band is a critical concept in understanding the electronic properties of materials. It influences how substances conduct electricity and plays a vital role in the development of modern technologies. As we continue to explore and manipulate materials at the atomic level, the significance of the valence band will only grow, paving the way for innovations in electronics, renewable energy, and beyond.

“价带”这个概念在固态物理和材料科学的研究中是基础性的。理解这个术语需要掌握电子在原子内的排列方式及其在固体材料中的相互作用。“价带”特指包含原子最外层电子的能带，这些电子参与化学键合和电导率。这些电子至关重要，因为它们决定了材料的电气特性，包括物质是导体、半导体还是绝缘体。进一步阐述，在固体中，原子紧密堆积在一起，它们的外层电子与邻近原子的电子重叠。这种重叠导致了能带的形成，其中“价带”充满电子，而下一个更高能量的能带，即导带，可能部分填充或为空。两个能带之间的间隙称为带隙，它在决定材料的电气特性方面起着关键作用。在导体中，“价带”和导带重叠，使得电子能够自由移动并导电。在半导体中，带隙足够小，以至于热能可以激发一些电子从“价带”跃迁到导带，从而实现有限的导电性。另一方面，绝缘体具有较大的带隙，这意味着“价带”中的电子无法轻易跃迁到导带，导致导电性差。对“价带”的理解不仅对理论物理至关重要，而且对技术中的实际应用也至关重要。例如，半导体器件（如晶体管和二极管）的开发在很大程度上依赖于操纵“价带”的性质。工程师和科学家可以通过引入杂质来修改材料的电子特性，这一过程称为掺杂。通过添加某些元素，他们可以创建n型或p型半导体，这两者具有不同的载流子浓度，并且对于制造高效电子设备是必不可少的。此外，纳米技术和材料科学的进步使得对具有独特“价带”特性的材料的探索成为可能。例如，石墨烯由于其独特的能带结构而表现出显著的电导性，其中“价带”和导带在某些点上相接触，使电子能够以最小的阻力移动。同样，对拓扑绝缘体的研究揭示了一些材料在其体相状态下具有绝缘特性，但在其表面上具有导电状态，这同样与“价带”的行为有关。总之，“价带”是理解材料电子特性的关键概念。它影响物质的导电方式，并在现代技术的发展中发挥着重要作用。随着我们继续在原子水平上探索和操纵材料，“价带”的重要性只会增加，为电子、可再生能源等领域的创新铺平道路。