Naslov
Optical properties of porous silicon on an insulator layer

Autori
Balarin, Maja ; Gamulin, Ozren ; Ivanda, Mile ; Kosović, Marin ; Ristić, Davor ; Ristić, Mira ; Musić, Svetozar ; Furić, Krešimir ; Krilov, Dubravka

Izvornik
Journal of molecular structure (0022-2860) 993 (2011), 1-3; 208-213

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
porous silicon ; photoluminescence ; Raman spectroscopy ; quantum confinement model ; SEM

Sažetak
N – type silicon wafers, consisting of 280 um tick upper and 20 um tick lower layers, were electrochemically etched in hydrofluoric acid (HF) ethanol solution. The resistivity of upper layer was 0.015 Ohmcm, while the lower layer was much worse conductor with resistivity of 2 Ohmcm. Porous silicon (PS) samples were produced by etching the rough (upper) side of a single-side polished wafers at the constant current density. The process of etching was monitored at different HF concentrations. The samples were investigated by Raman spectroscopy, photoluminescence (PL) and scanning electron microscopy (SEM). Due to the roughness of unpolished surface different surface orientations were exposed to electrochemical etching, which resulted in different etching speed and consequently different morphology (plateaus, valleys) produced by etching. The porous plateaus showed the most intensive PL observable even with optical microscope. PL spectra exhibited the decrease of peak intensity and the blue shift of maximum with an increase of HF concentration. The presence of nanometer size Si structures was confirmed by the broadening and the red-shift of transversal optical (TO) phonon band in the Raman spectra. The quantum confinement model was used to determine the average size of these structures. SEM images showed the pores of different morphology with several nanometers in diameter. The largest pores and the thinnest walls were obtained when etched with the lowest HF concentration.

Izvorni jezik
Engleski

Znanstvena područja
Fizika, Kemija

Napomena
Rad je prezentiran na skupu XXXth European Congress on Molecular Spectroscopy "Molecular spectroscopy and molecular structure", održanom od 29.08.-03.09.2010., Florence, Italija.

POVEZANOST RADA