Method of controlling spontaneous emission from porous silicon fabricated using pulsed current etching

作者：Ali N K; Hashim M R^*; Aziz A Abdul; Hamammu I

来源：Solid-State Electronics, 2008, 52(2): 249-254.

DOI：10.1016/j.sse.2007.08.022

• porous silicon
• photoluminescence
• quantum confinement

We present a new technique for porous silicon formation based on pulsed current anodic etching. The technique offers the possibility of fabricating luminescent material with selective wavelength emission depending on cycle time (T) and pause time (T-off) of pulsed current during the etching process. Nanostructural nature of the porous layer has been demonstrated by X-ray diffraction (XRD) analysis and confirmed by photoluminescence (PL) and Raman spectroscopy. PL measurements of pulsed anodic etching porous silicon showed variety of emission wavelengths with strong intensity. Raman scattering from the optical phonon in porous silicon showed the redshift of the phonon frequency, broadening and increased asymmetry of the Raman mode with increasing T-off. Using the phonon confinement model, the average diameter of Si nanocrystallites has been estimated from 3.5 to 5.3 nm. Both Raman and PL results were explained using quantum confinement models. A good agreement is obtained between the results from PL and Raman spectroscopy of the etched Si samples.

• 出版日期2008-2