概括
微波辅助化学蒸汽沉积 (MACVD) 产生了具有高载体流动性的多晶钻石薄膜. 然而,颗粒内部的缺陷限制了载体漂移的长度,影响了整体性能.
科学领域:
- 材料科学 材料科学 材料科学
- 固态物理 固态物理
- 纳米技术 纳米技术
背景情况:
- 聚晶钻石薄膜是使用各种技术合成的,包括微波辅助化学蒸气沉积 (MACVD).
- 了解电运输特性,如载体移动性和寿命,对于评估钻石膜质量和潜在应用至关重要.
研究的目的:
- 为了研究由MACVD合成的多晶钻石薄膜的电传输特性.
- 测量载体的移动性和寿命,并分析影响这些属性的因素.
主要方法:
- 暂时光导度测量被用来研究钻石膜.
- 从实验数据来确定载体的移动性和寿命.
主要成果:
- 在低载体密度 (<1015 cm−3) 的情况下,测量到的载体移动性最高为50 cm2/Vs.
- 由于电子孔散射,载体的移动性在较高密度下降.
- 导体寿命被推断为大约40皮秒,导体漂移的长度受到粒内缺陷的限制.
结论:
- 与质量较差的DC-等离子膜相比,MACVD合成的多晶钻石薄膜表现出有希望的载体移动性.
- 这些薄膜的性能受到颗粒大小和颗粒内部缺陷的显著影响,这些缺陷限制了载体运输.
- 需要进一步优化合成条件,以接近单晶天然钻石的电特性.
相关概念视频
Electrical Transport
The electrical transport property of a material is defined by its resistance and conductivity. Resistance is the measure of a material's ability to resist the flow of electric current, while conductivity gauges its ability to allow the current to pass through, depending on the geometry of the measurement cell, such as electrode spacing and area. Conductivity is measured in Siemens (S). There are different types of conductance, including specific conductance, equivalent conductance, and molar...
Carrier Transport
The generation of electrical current in semiconductors is fundamentally driven by two mechanisms: drift and diffusion. These processes are essential for the functionality and performance of semiconductor-based devices.
Drift Current:
The drift of charge carriers is started by an external electric field (E). Charged particles, such as electrons and holes, experience an acceleration between collisions with lattice atoms. For electrons, this results in a drift velocity (vd) given by:
Drift Current:
The drift of charge carriers is started by an external electric field (E). Charged particles, such as electrons and holes, experience an acceleration between collisions with lattice atoms. For electrons, this results in a drift velocity (vd) given by:
Semiconductors
There is variation in the electrical conductivity of materials - metals, semiconductors, and insulators that are showcased with the help of the energy band diagrams.
Metals such as copper (Cu), zinc (Zn), or lead (Pb) have low resistivity and feature conduction bands that are either not fully occupied or overlap with the valence band, making a bandgap non-existent. This allows electrons in the highest energy levels of the valence band to easily transition to the conduction band upon gaining...
Metals such as copper (Cu), zinc (Zn), or lead (Pb) have low resistivity and feature conduction bands that are either not fully occupied or overlap with the valence band, making a bandgap non-existent. This allows electrons in the highest energy levels of the valence band to easily transition to the conduction band upon gaining...
Drift Velocity
The high speed of electrical signals results from the fact that the force between charges acts rapidly at a distance. Thus, when a free charge is forced into a wire, the incoming charge pushes other charges ahead due to the repulsive force between like charges. These moving charges move the charges farther down the line. The density of charge in a system cannot easily be increased, so the signal is passed on rapidly. The resulting electrical shock wave moves through the system at nearly the...
Theory of Metallic Conduction
The conduction of free electrons inside a conductor is best described by quantum mechanics. However, a classical model makes predictions close to the results of quantum mechanics. It is called the theory of metallic conduction.
In this theory, Newton's second law of motion is used to determine the acceleration of an electron in the presence of an applied electric field. Then, its velocity is expressed via this acceleration.
An electron moves through the crystal, containing positive ions,...
In this theory, Newton's second law of motion is used to determine the acceleration of an electron in the presence of an applied electric field. Then, its velocity is expressed via this acceleration.
An electron moves through the crystal, containing positive ions,...
Non-ohmic Devices
In most substances, the current flow is proportional to the voltage applied to it. A simple relationship between the values of current, voltage, and resistance is known as Ohm's law. Nonohmic devices do not exhibit a linear relationship between voltage and current. One such device is the semiconducting circuit element known as a diode. A diode is a circuit device that allows current flow in only one direction.
Consider a simple circuit consisting of a battery, a diode, and a resistor. A diode...
Consider a simple circuit consisting of a battery, a diode, and a resistor. A diode...


