摘要 |
<p>The conventional photoemitting surfaces cannot efficiently absorb incident long-wavelength photons. In the photoemitting surface according to this invention, the absorption of incident photons, and the generation of electron-hole pairs take place between sub-bands of conduction bands or between sub-bands and the bottoms of the conduction bands, and the generated photoelectrons are further accelerated by a internal electric field. Accordingly the photoemitting surface can be sensitive to incident long-wavelength photons. In the electron tubes using the photoemitting surface according to this invention, and the photodetecting devices using these electron tubes, photometry, imaging, etc. can be effectively performed at low illuminance. <IMAGE></p> |