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"Super Semiconductor"-Zinc Sulfide

wallpapers Energy 2020-06-01 >
Thousands of materials in this world can be roughly divided into two categories-brittle and plastic. We can compare these two types of materials to "biscuits" and "nougat". Biscuits are brittle and can break easily when stressed. This is not the case with nougat. After being confirmed, it will undergo a large deformation before breaking, which can be called plasticity.
Whether a material is "biscuit type" or "nougat type" depends mostly on its properties, including constituent elements, microstructure and processing technology. For example, gold is a typical "nougat type", it has good extensibility, even if we use a hammer to knock the gold nugget into thin gold foil, it will not break. Environmental conditions can also affect plasticity and brittleness. The most typical example is temperature. Generally speaking, the lower the heat, the easier the material becomes brittle-in the northeast of winter, the nougat can be broken directly outdoors. The silicon material is brittle at room temperature and becomes plastic at a high temperature of 750 ° C.
As we all know, semiconductor materials play a vital role in today's electronics. Mobile phones, computers, TVs, radios, these electronic products that we get along with day and night are inseparable from semiconductors. At room temperature, most common semiconductor materials are brittle, and this brittleness is very likely to cause device failure.
Is there a way to improve the performance of semiconductors and change it from "cookie type" to "nougat type"?
Yes, and it's straightforward, that is-"Don't shine".
Scientists in Nagoya, Japan, discovered that a dark environment could transform a semiconductor material from brittle to plastic. This time the protagonist is zinc sulphide (ZnS). This material, also called sphalerite, is a gem. Common sphalerite shows yellow or brown colours because it contains impurities. Pure sphalerite is transparent and widely used in optoelectronic devices.
As the sulphide zinc sulphide, the yellow colour is because it contains trace metal impurities. Under normal circumstances, this kind of zinc sulphide material is a typical "biscuit type", and it is basically "cracked" when subjected to external forces. Researchers have found that if mechanical testing of zinc sulphide crystals is performed in completely dark conditions, it can exhibit extraordinary "plasticity".
At room temperature, the experimenters applied three light conditions to zinc sulphide: one was ordinary white light, the second was ultraviolet light, and the third was complete darkness. The experimental results show that under the irradiation of natural white light and ultraviolet light, the zinc sulphide crystals show the universal brittleness-applying sufficient force to the material will immediately break or even break. On the contrary, if in a completely dark environment, it is found that the zinc sulphide crystals can deform up to 45% without being destroyed. In other words, although the small glass was squashed in half, it remained stable.
In fact, in some other semiconductor materials, there are also examples where the mechanical properties of the material are affected by excessive light. For example, some studies have found that the irradiation of ultraviolet light can make a specific semiconductor material hard, and a unique concept is used to describe this phenomenon, the so-called "photoelastic effect". However, no one has ever realized that the completely black environment affects the material. The plastic effect is so significant.
Why is there such a magical phenomenon? This needs to be explained from the micro-level. To better help everyone understand this problem, we need to introduce a new term first, called "dislocation".
"Dislocation" means that the position is wrong. It means that the location of the atoms is wrong. In materials such as metals and semiconductors, atoms are initially arranged in a specific manner. And if the position of a particle is shifted, or a bit is lost somewhere, then a "dislocation" will form.
When the concept of dislocations was first proposed, it was just a preliminary conjecture. However, it can reasonably explain many experimental phenomena that were incomprehensible in the past, so many scholars have supported it. With the development of science and technology, especially the leap in advanced microscope technology, people can finally observe the microstructure of the atomic level, and finally confirmed the existence of dislocations.
Returning to zinc sulphide again, under the influence of different light conditions, the electrons in the crystal will have different distribution states. The distribution of particles in the dark is conducive to more dislocations. Moreover, the confusion generated at this time is "slip type"; this unique form of disorder makes the material more prone to deformation. As the differences in these atomic levels gradually accumulate, on the scales visible to the naked eye, the zinc sulphide crystals eventually transformed from "biscuits" to "nougat".
The effect of dislocations is much more than deformation. If you observe enough, you will find that the zinc sulphide flattened in the dark, the colour changed from transparent to orange-brown. As the saying goes, "phases are born from the heart", the colour of the crystal is often the appearance of deep-level information such as its composition and a microstructure-a large number of dislocations cause the electrical and optical properties of zinc sulphide to change, which is reflected in colour on.
In this study, the scientists not only showed the "transformation method" of zinc sulphide, revealed the photosensitive properties of crystal mechanical properties, but also provided new ideas for semiconductor design-maybe the future semiconductor processing and manufacturing process needs to be turned on Do not turn on the lights to control it.
The seemingly ordinary zinc sulphide, because of the extraordinary nature of the incarnation of "super semiconductor". I don't know how many mysteries there are in the world, how many secrets are waiting to be discovered.
Trunnano is one of the world's largest producers of zinc sulphide nanomaterials, as well as various sulphide nanoproducts. If you want to know about sulphide nanoproducts, please contact Dr Leo, email: brad@ihpa.net.

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