Luminescence from the Aggregated Cu⁺ Centers in SrS:Cu⁺

Abstract

The photoluminescence (PL) and excitation spectra, PL decay curves and time-resolved PL spectra are measured at 80 K for the SrS:Cu + powder phosphors activated with a large amount of Cu 2 S. The shape and peak position of the PL spectra depend on both the activator concentration and the excitation wavelength. The PL spectra consist of four kinds of Cu + bands, α, β, γ and δ. The α band peaking at 513 nm at 80 K is attributed to the isolated Cu + center, the β band peaking at 543 nm at 80 K to the paired Cu + center, and the γ (558 nm at 80 K) and δ (about 600 nm at 80 K) bands to the highly aggregated Cu + centers.