First results on light emitting diodes in porous silicon were reported in 1991. They showed a quantum efficiency of 10-7 to 10-5 and an orange spectrum. Over the last year some progress was achieved:
- By applying UV-light during the etching blue and green light emitting diodes in porous silicon are fabricated.
- When a p/n junction is realized within the porous region, a quantum efficiency of 10-4 is obtained.