光电效应中的峰值频率和频率上限

Peak Frequency and Upper Frequency Limit in the Photoelectric Effect

爱因斯坦对光电效应的解释已经过去一百多年,在这一百多年里,光敏材料得到了飞速发展,通过对光敏材料频率响应曲线的分析,可以看到,光敏材料频率响应曲线都有一个峰值频率和上限频率,这是传统光电效应解释中“只要光频率大于截止频率,就可以激发出光电子”的概念难于解释的。根据原子能级理论和共价电子理论,可以认为光敏晶体中的共价电子单独形成了一个共价电子共有能级,共价电子就运行在这个能级的等能面上,当外界光线的光子能量hf与光敏材料的价电子能级和自由电子能级差相等时,光线的光子能量传递给光敏材料中的价电子,形成自由电子。对外光电效应的光敏材料,自由电子在外电场的作用下,逃离晶体形成光电子;对光电流效应(内光电效应)的光敏材料,在外电压的作用下,形成电流。

Einstein’s explanation of the photoelectric effect has passed for more than 100 years. In the past 100 years, photosensitive materials have developed rapidly. Through the analysis of the frequency response curves of photosensitive materials, it can be seen that the frequency response curves of photosensitive materials have a peak frequency and an upper limit frequency, which is difficult to explain in the traditional photoelectric effect interpretation of the concept of “As long as the optical frequency is greater than the cutoff frequency, photoelectrons can be excited”. According to the atomic energy level theory and covalent electron theory, it can be considered that the covalent electrons in the photosensitive crystal alone form a covalent electron common energy level, and the covalent electrons operate on the iso-energy surface of this energy level. When hf is equal to the difference between the valence electron energy level and free electron energy level of the photosensitive material, the photon energy of the light is transferred to the valence electrons in the photosensitive material to form free electrons. For photosensitive materials with an external photoelectric effect, free electrons escape from the crystal under the action of an external electric field to form photoelectrons;for photosensitive materials with a photocurrent effect (internal photoelectric effect), the current is formed under the action of external voltage.