Structural and Optical Properties of N-Type and P-Type Porous Silicon Produced at Different Etching Time
1PHYSICS, UNIVERSITI PUTRA MALAYSIA, SERDANG, Selangor, Malaysia
2Department of Physics, Faculty of Science, Universiti Putra Malaysia, 43400 UPM , Serdang, Selangor, Malaysia, Selangor, Malaysia
3Department of Applied Sciences, Universiti Teknologi MARA (UiTM), 13500 Permatang Pauh, Permatang Pauh, Penang, Malaysia
*Email Address : azurahanim@upm.edu.my
Abstract : In this study, porous silicon thin films with different etching time (10 and 13 minutes) were successfully fabricated on both n- and p-type silicon substrate using electrochemical etching technique. This technique was employed as it is easy, inexpensive, not required complex apparatus and not limited to one type of silicon wafer. XRD, SEM, PL and Raman Spectroscopy have been used to characterize the influence of varying etching time on structural and optical properties of prepared porous silicon. XRD indicated that n- and p-type porous silicon have crystallite size ranging from 9.00 - 32.0 nm. By increasing etching time, the crystallite size increased. SEM images revealed that porosity of porous silicon increase proportionally to the etching time with average pore size around 2 - 18 μm and p-type showing higher porosity than n-type. The emission spectra of porous silicon characterized using PL showed peak emission in the orange red luminescence with the wavelength range of 600 - 650 nm. PL and Raman intensity increased with the increasing of etching time. Raman analysis demonstrated the symmetric peak position for different intensity and width. Intensity and values of FWHM for p-type is higher compared to n-type porous silicon.
Keywords : porous silicon,electrochemical etching ,photoluminescence, n-type, p-type,