SEMICONDUCTOR PHYSICS Sakshi Education（半导体物理学Sakshi教育）.pdfVIP

SEMICONDUCTOR PHYSICS Introduction: A semiconductor is a material that has a resistivity value in between that of a conductor and an insulator. The conductivity of a semiconductor material can be varied under an external electric field. Devices made from semiconductor materials are the foundation of modern electronics, including ratio, computers , telephones, and may other devices. Semiconductor devices include the transistor, many kinds of diodes including the light emitting diode, the silicon controlled rectifier, and digital and analog integrated circuits. Solar photovoltaic panels are large semiconductor devices that directly convert light energy into electrical energy. In a metallic conductor, current is carried by the flow of electrons. In semiconductors, current can be carried either by the flow of electrons or by the flow of positively charged holes in the electron structure of the material. Silicon is used to create most semiconductors commercially. So many other materials are used, including germanium, gallium arsenide. A pure semiconductor is often called an intrinsic material and then allowing the melt to solidify into a new and different crystal. This process is called doping. Question: Explain the preparation of semi conducting materials? Answer: Preparation of semiconductor materials: Semiconductors with predeictable, reliable electronic properties are necessary for mass production. The level of chemical purity needed is extremely high because the presence of impurities even in very small proportions can have large effects on the properties of material. High degree of crystalline perfection is also required, since faults in crystal structure ( such as dislocations, twins and stacking faults) interfere with the semi- conducting properties of the material. Crystal