Excitation effects and luminescence stability in porous SiO2:C layers

: Vasin A, Rusavsky A, Nazarov A, Lysenko V, Rudko G, Piryatinski Y, Blonsky I, Salonen J, Makila E, Starik S

Publisher: WILEY-V C H VERLAG GMBH

: 2012

: physica status solidi (a)

: PHYSICA STATUS SOLIDI A-APPLICATIONS AND MATERIALS SCIENCE

: PHYS STATUS SOLIDI A

: 6

: 209

: 6

: 1015

: 1021

: 7

: 1862-6300

DOI: https://doi.org/10.1002/pssa.201100815(external)

White-light emitting porous SiO2:C layers on silicon wafers have been fabricated by oxidation of carbonized porous silicon. The study was focused mainly on the identification of the mechanism of light emission and photo-induced degradation. The effect of carbonization temperature and exposure to intense ultraviolet irradiation on the photoluminescence (PL) properties was studied by steady state and time-resolved PL measurements. Two types of photo-induced degradation phenomena were observed: reversible and irreversible. The irreversible degradation is suggested to be associated with photo-induced chemical interaction of light emitting material with atmospheric oxygen. It is demonstrated that irreversible degradation can be reduced by encapsulation of the light-emitting material. The structural configuration of light-emitting centers and mechanism of reversible degradation are discussed.