Semiconductor electrodes having regions of graded composition exhibiting photoluminescence and electroluminescence
US4543511A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 24, 1983 |
| Grant date | Sep 24, 1985 |
| Priority date | — |
| Expiry date | Mar 24, 2003 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02E10/50
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A photoelectrochemical cell (10) is disclosed which has a semiconductor substrate (11) formed of a solid solution of three metal and non-metal elements, with two like elements varying in concentration with depth from an exposed surface (13) of the substrate (11). The band gap energies between the valence and conduction bands varies with the concentration of the two elements from the surface, with the band gap energies being in a proper range to provide emitted light in response to light or electrical stimulation. An electrolyte (14) is maintained in contact with the exposed surface and a counterelectrode (15) is immersed in the electrolyte such that a voltage applied between a counterelectrode (15) and the substrate (11) will vary the color of light emitted from the exposed surface (13) in response to incident light or by stimulation from the electrical current passing through the substrate. Preferred materials for the substrate are cadmium and selenium, with sulfur being diffused into the exposed surface and substituted in the lattice for selenium.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.