Anodization Current Density Independent Photoluminescence of Porous Silicon

Abstract

Porous silicon (PS) is usually prepared by means of the anodization under constant current density, and fabrication of PS is a key step towards the realization of all-silicon electronic devices. It is a general belief that the photoluminescent properties of electrochemically etched PS depend on the anodization current density. In this work, we electrochemically prepared a series of PS films in the electrolyte of hydrofluoric acid by varying anodizing current density in the range of 1-70 mA/cm2. In spite of the different anodizing current density, the peak wavelength of the photoluminescence spectrum of the electrochemically anodized PS does not depend on the anodization current density. SEM has been utilized to characterize the morphology of the prepared PS films, and the mechanism is discussed for the anodization current independent photoluminescence of PS.

TEMPERATURE DEPENDENT CHARACTERISTICS OF SrAl2O4:Dy 3+PHOSPHOR

“…All the spectra at the three different temperatures show a nearly same characteristic peak at 442nm, 477nm, 582nm and 648nm when excited at 325nm wavelength. The peak at 442nm corresponds to the host material, and the other three peaks correspond to 46 F H  transitions of Dy 3+ ions, respectively [17].These three characteristic emissions peak gives the information of Dy 3+ ions acting as luminescence centres in the SrAl 2 O 4 host. Also, we get maximum intensity at 1000ºC, which indicate a good annealing temperature for future analysis.…”

Annealing-assisted optimization for persistency of afterglow of SrAl2O4:Eu2+/Dy3+ microparticles for forensic detection

“…Under the UV excitation, the synthesized samples revealed green photoluminescence, which conrms the purity of the obtained SrAl 2 O 4 phase in the presence of Eu 2+ /Dy 3+ dopants. 36 There is a possibility of a change in colour of the photoluminescence emission due to the presence of different dominant phases. For example, SrAl 4 O 7 has orange colour, and SrAl 16 O 25 has red as the dominant colour for the same doping of Eu and Dy ions.…”