Semiconductor materials have conductive properties, and their conductivity is between conductors and insulators (resistivity is about 1mΩ/cm-1GΩ/cm). When the ambient temperature changes, the frequency of the crystal lattice vibration of the semiconductor material changes, resulting in a change in resistance, thereby changing the conductivity. Therefore, a semiconductor is a material with a controllable range of conduction from an insulator to a conductor. According to the chemical composition of semiconductors, it can be simply divided into elemental semiconductors, inorganic composite semiconductors, organic composite semiconductors, and amorphous and liquid semiconductors. The controllable conductivity of semiconductors enables applications in integrated circuits, communication systems, photocatalysts, power conversion, lighting and other fields.
Figure 1. The role of semiconductor materials in temperature control systems (Main controller and Auxiliary controller are semiconductor)
- Lighting materials: Semiconductor light sources based on semiconductor light-emitting diodes (LED) have the advantages of small size, low heat generation, low power consumption, long life, fast response speed, impact resistance, environmental protection, high efficiency and energy saving. Under the overall requirements of green development, LED-based semiconductor lighting products have become a new generation of light sources after incandescent lamps and fluorescent lamps. At present, LEDs are also used in large-screen displays, traffic lights, mobile phone backlights, etc., and have broad application prospects.
- Communication system: In the communications industry, semiconductors are used to prepare core technology materials such as radio frequency chips, baseband chips, and filter piezoelectric materials. The semiconductor compound contains compounds such as silicon carbide, gallium nitride, and gallium arsenide, which have multiple functions such as high electron mobility, large forbidden band width, and direct band gap, achieving high-frequency filtering processing, fast response, and high spectral efficiency.
- Photocatalyst: Semiconductors can be used as photocatalysts to treat organic pollutants in water, organic synthesis and inorganic synthesis. It has the advantages of mild reaction conditions, high efficiency, and wide application range. In terms of water treatment, semiconductor applications are the most prominent. Its strong oxidizing ability can decompose and destroy many pesticides, fuels, surfactants, and odorous substances in many sewage, and the sewage treatment effect is better.
- Power conversion: For the use of electrical appliances, the mutual conversion of alternating current and direct current is very important, and it is a necessary protection for electrical appliances. The semiconductor material silicon carbide has high breakdown voltage, wide band gap, and high thermal conductivity. It is suitable for applications where power density and switching frequency are high, and can be used as a power conversion device.
- Flexible display screen: Flexible displays have the unique advantages of being able to bend and deform, and are used in mobile phones, glasses, watches and other products. A new type of semiconductor with silver atoms as the main component has ductile and bendable properties similar to metals, and at the same time has the conductivity of semiconductors, and has been widely used in the field of electronic development.
- Xiaoyu Sun, Chengyin Wang, Dawei Su, Guoxiu Wang, Yunhao Zhong. Application of Photocatalytic Materials in Sensors [J]. Advanced Materials Technologies 2020, 5(5), 1900993.