What is the working principle of semiconductor cooling wafers?

At 20:30 on July 22, the facilities construction project of the cold chain loA refrigeration chip, also known as a thermoelectric semiconductor refrigeration module or Peltier, refers to a chip that is divided into two sides, one side absorbs heat and the other side dissipates heat, playing a role in heat conduction. It itself does not produce cold. A cooling plate is a cooling device composed of semiconductors. With the development of modern semiconductors, they have had practical applications, namely the invention of cooling sheets. Its working principle is that a DC power supply provides the energy required for electron flow. After connecting to the power supply, the electronic negative electrode (-) is composed of two ceramic plates, one at the cold end and the other at the hot end. The cold end is connected to a heat source for cooling. In the past, CPUs used cooling plates, which were cooled by the cold end, while the heat from the hot end had to be discharged by a fan. The cooling plates are also used to make cold/hot insulation boxes for vehicles. The cold end can be used as a cold drink machine, and the hot side can be used to keep warm.gistics center of the high-speed railway station in Qiubei County...

Semiconductor cooling sheets are thin and lightweight, small in size, do not take up space, and can be carried. It can be made into an electric cooling/heating incubator for vehicles, placed on the vehicle without occupying any space, and can be turned into a refrigerator and incubator. In summer, you can put a few bottles of beverages, which can be instant ice drinks, and in winter, they can become insulated boxes. The typical structure of a cooling sheet is composed of many N-type and P-type semiconductor particles arranged mutually, while NP is connected to a general conductor to form a complete circuit, usually copper, aluminum, or other metal conductors. It is sandwiched between two ceramic pieces, just like a Sandwich cookie. Ceramic chips must be insulated and have good thermal conductivity. The appearance of the cooling sheet describes the principle of N-type and P-type semiconductors in detail as follows: if pentavalent elements are uniformly doped in germanium or silicon, each pentavalent element will form a Covalent bond with adjacent tetravalent germanium or silicon atoms, because Valence electron will combine with each other to form a Covalent bond and another electron will be added. Due to the addition of electrons to a pentavalent element, it is also known as a donor atom. In N-type semiconductors, the majority of free electrons are generated by adding pentavalent elements, hence they are referred to as majority carriers.

If the trivalent elements are uniformly doped in germanium or silicon, each trivalent element will form a Covalent bond with the adjacent tetravalent germanium or silicon atoms, because the Valence electron will combine with each other to form a Covalent bond. The absence of an electron will result in vacancies in the atom, which is called an electron hole. Due to the addition of trivalent elements leading to vacancies, trivalent elements are also known as acceptor atoms. The holes generated by adding trivalent elements are the main carriers in P-type semiconductors. The number of electron holes generated by heating to destroy the Covalent bond is very small, so the electrons in the P-type semiconductor are called minority carriers.