Metal-aided electrochemical etching of silicon for ambient red to blue photoluminescence

Abstract

Ambient full-color photoluminescence from porous silicon has been realized through electrochemical etching aided by an "oxidative'' metal such as Zn without any postanodizing treatment. The emission can be tuned to any wavelength in the visible range by simply changing anodizing current density from 20 to 100 mA/cm(2). The luminescence intensity is high enough that all colors are visible to naked eyes. Aging behavior of the red, green, and blue photoluminesence is also investigated over a three-month time span. While the pinning of the peak wavelength occurs with aging at a certain level for all the peaks, the blue emission always gets pinned at around 420 nm whether the initial emission is green or blue.