Scientists find non-toxic infrared semiconductor material

Semiconductor materials are a class of semiconductor materials with semiconductor properties (conductivity between conductors and insulators, resistivity is about 1mΩ·cm~1GΩ·cm range), electronic materials that can be used to make semiconductor devices and integrated circuits, are more important. However, many existing infrared semiconductors contain toxic chemical elements, such as cadmium and tellurium. In a new study, scientists have discovered that the compound Ca3SiO, a direct-bandgap semiconductor composed of calcium, silicon and oxygen, is inexpensive to produce, non-toxic, and has the potential to be used in infrared LEDs and infrared detector elements. It is reported that infrared electromagnetic waves have many uses, such as optical fiber communication, photovoltaic power generation and night vision equipment. However, semiconductors capable of emitting infrared radiation (ie, direct transition semiconductors such as cadmium mercury telluride and gallium arsenide) contain toxic compounds. Infrared semiconductors that do not contain toxic chemical elements generally cannot emit infrared radiation (ie, indirect bandgap semiconductors). Traditionally, the semiconducting properties of materials, such as the energy band gap, are controlled by combining 2 chemical elements (such as III and V or II and VI) located to the left and right of group IV elements. In this traditional strategy, by using heavier elements, the energy band gap becomes narrower: this idea has led to the development of toxic direct transition semiconductors, such as cadmium mercury telluride and gallium arsenide. To discover infrared semiconductors free of toxic elements, the research team took an unconventional approach: They focused on the crystal structure of the silicon atom as a tetravalent anion rather than the normal tetravalent cation state. The group selected oxysilicides (such as Ca3SiO) and oxygermanides with anti-perovskite crystal structures, synthesized them, evaluated their physical properties and performed theoretical calculations. The results show that these compounds have great potential as direct transition semiconductors. These compounds with small direct band gaps may be efficient at absorbing, detecting and emitting long infrared wavelengths, even when they are processed into thin films, making them very promising near-infrared semiconductor materials for infrared sources and detection device.