外光電效應(yīng)
    半導(dǎo)體中電子吸收較高能量的光子而被激發(fā)成為熱電子，有可能克服晶格場(chǎng)的束縛逸出體外成為自由電子,這又稱光電子發(fā)射效應(yīng)。圖2是一個(gè)具有理想表面的半導(dǎo)體的能帶圖，EC、EV分別表示導(dǎo)帶底和價(jià)帶頂,E0為體外真空能級(jí),x為電子親和勢(shì)(表示導(dǎo)帶底的電子逸出體外所需克服的晶體束縛能),EF為費(fèi)米能級(jí)位置,φ為逸出功,ET=x+EV為光電子發(fā)射閾能。

 

External photoelectric effect
Electrons in semiconductors absorb high-energy photons and are excited to become hot electrons. It is possible to overcome the binding of lattice fields and escape out of the body to become free electrons, which is also called photoelectron emission effect. Fig. 2 is the energy band diagram of a semiconductor with an ideal surface. EC and ev respectively represent the bottom of the conduction band and the top of the valence band. E0 is the in vitro vacuum energy level, X is the electron affinity potential (representing the crystal binding energy to be overcome for the electrons at the bottom of the conduction band to escape out of the body), and EF is the position of the Fermi energy level, φ Is the escape work, et=x+ev is the photoelectron emission threshold energy.