Infrared semiconductor materials
Infrared radiation is a form of electromagnetic radiation with wavelengths longer than those of visible light. It is sometimes called infrared light. As with all types of electromagnetic radiation, infrared is affected by diffraction and polarization, and so can be used to detect and characterize many features of matter, such as chemical bonds, crystal structure and temperature distribution. Consequently, the utilization of infrared radiation is widespread in many engineering and scientific disciplines. In fact, the majority of infrared applications use materials such as semiconductors as optoelectronic materials. These materials can be used to convert infrared radiation into electrical signals, or to emit infrared radiation itself.
In order to generate or detect infrared radiation, semiconductor materials are extensively used. Semiconductors not only have the ability to absorb infrared radiation, but also have a wide range of properties which make them ideal for use in optoelectronic devices. These properties include a high resistivity, good thermal conductivity, low energy consumption, light weight, low cost, and wide range of power capabilities. Since semiconductors are also known for their sensitivity to light, they can also be used for optical sensing applications.
In terms of structure, semiconductors can be divided into two categories namely intrinsic and extrinsic. Intrinsic semiconductors are made from a pure material such as pure silicon or germanium, while extrinsic semiconductors consist of argon impurities in doped silicon. Unlike the intrinsic semiconductor materials, these extrinsic materials possess a wide range of electrical properties, and so are well suited for optoelectronic applications. The most common extrinsic semiconductor materials used in infrared technology are gallium arsenide, gallium nitride and indium gallium arsenide phosphide.
The properties of these materials make them ideally suited for a number of infrared applications. For instance, gallium arsenide is often used in daylight optical imagers, since its absorption characteristics make it perfect for detecting various frequencies of infrared radiation. Similarly, gallium nitride and indium gallium arsenide phosphide are used for the production of efficient infrared lasers, since these materials have a wide range of emission characteristics, making them suitable for producing radiation with different wavelengths.
Moreover, infrared semiconductor materials can also be used for the production of thermal imaging cameras. Thermal imaging cameras use infrared radiation to obtain images by detecting differences in infrared radiation emitted from an object. The semiconductors used for thermal imaging cameras can measure radiation from a source in a range of wavelengths, from the near-infrared to the mid-infrared.
In conclusion, semiconductor materials are ideal for use in optoelectronic devices and infrared applications due to their wide range of electrical and optical properties. These materials can be used to convert infrared radiation into electrical signals and to detect and characterize many features of matter. Furthermore, they are instrumental in the production of efficient infrared lasers and thermal imaging cameras. Thanks to their versatility, semiconductor materials have become indispensable in infrared technology.
