High-quality solar Pir motion sensor light Tip: Is the electron in the semiconductor really lighter than the free electron?

What is the speed when an electric field is applied to an electron (charge e) in a semiconductor? The force generated by the applied electric field is expressed by eF, and the time required for electron scattering is used to indicate that the electron is subjected to the impulse of cEr until it is incident. This impulse is equal to the increase of electron momentum. If m is used to represent the mass in the semiconductor, then m"v=eE, speed=eEtm'e. The probability of its movement is the ratio of velocity to electric field, so F=ertm, we The term "m" is called the effective mass of electrons in an effective mass semiconductor. This value is particularly small in our macroscopic terms, but it is normal in comparison to the microscopic world.

How much is lighter than free electronics?

When we measure the electron mobility, we find that m is much smaller than the quality of free electrons. Looking at the electrons, the effective mass of silicon is 0.32 times that of free electrons, and the surface calcium is only 0.067 times. Therefore, after the electric field is applied, the electron velocity is much larger than that of the free electron. This is actually about the effective quality of electronics. The electrons in high-quality solar Pir motion sensor lights are also the same.