Avaspec hs2048xl

The PL excitation spectra were recorded using a spectrometer (Varian Carry 50) in the 600–250 nm range, monitored at 650 nm for ${\text{Ca}}_{1-\mathrm{x}}{\text{S:Eu}}_{\text{x}}^{2+}$ 614 nm for ${\text{Sr}}_{1-\mathrm{x}}\text{S:}{\text{Eu}}_{\text{x}}^{2+}$ and 514 nm for the SAED phosphors. The phosphors were placed in 1 mm quartz cuvettes during the measurement. The PL emission was recorded using a spectrometer (CCS200, Thorlabs) coupled with an optical fiber of 1 mm diameter (FP100URT, Thorlabs) after 450 nm LED excitation. To calculate the PLQY, an optical setup with a spectrometer (AvaSpec-HS2048XL, Avantes) coupled with an optical fiber (FP100URT, Thorlabs) to an integrating sphere (15 cm diameter, Lab sphere) was used. A 450 nm LED, controlled with a benchtop diode controller (ITC4001, Thorlabs) was used as the excitation source and was directed towards the sample in quartz cuvettes inside the integrating sphere where several measurements as described by de Mello et al. method were taken^{44 (link)}. Measurements of the empty sphere, direct and indirect excitation spectra, direct and indirect PL emission spectra, and black background were recorded, from which the PLQY was calculated.