Absolute determination of photoluminescence quantum efficiency using an integrating sphere setup

Abstract

An integrating sphere-based setup to obtain a quick and reliable determination of the internal quantum efficiency of strongly scattering luminescent materials is presented. In literature, two distinct but similar measurement procedures are frequently mentioned: a "two measurement" and a "three measurement" approach. Both methods are evaluated by applying the rigorous integrating sphere theory. It was found that both measurement procedures are valid. Additionally, the two methods are compared with respect to the uncertainty budget of the obtained values of the quantum efficiency. An inter-laboratory validation using the two distinct procedures was performed. The conclusions from the theoretical study were confirmed by the experimental data.

Counting the Photons: Determining the Absolute Storage Capacity of Persistent Phosphors

“…The spectrum must be corrected for the instrument response to yield a photon flux per wavelength interval ${\varphi }_{\gamma }\left(\lambda \right)$ [43]. The luminous efficacy and the average photon energy can then be determined using Equations (2) and (3), in combination with the known eye sensitivity curve $V\left(\lambda \right)$ [23]: $\eta =\frac{\int {\varphi }_e\left(\lambda \right)V\left(\lambda \right)\mathrm{normald}\lambda }{\int {\varphi }_e\left(\lambda \right)\mathrm{normald}\lambda }$ ${\stackrel{false¯}{E}}_{\gamma }=\frac{\int {\varphi }_{\gamma }\left(E\right)E\mathrm{normald}E}{\int {\varphi }_{\gamma }\left(E\right)\mathrm{normald}E}$ where ${\varphi }_e\left(\lambda \right)$ is the spectral radiant flux, which is related to the photon flux by ${\varphi }_e\left(\lambda \right)$d$\lambda ={\varphi }_{\gamma }\left(\lambda \right)\frac{hc}{\lambda }$d$\lambda$.…”

Identifying an efficient, thermally robust inorganic phosphor host via machine learning

“…The temperature was controlled using a Janis liquid nitrogen cryostat (VPF-100) and the emission spectra were collected from 80 to 500 K in 20 K increments using a λ ex  = 340 nm. The absolute (internal) photoluminescent quantum yield was determined by placing the samples encapsulated in the silicone resin inside a Spectralon-coated integrating sphere (150 mm diameter, Labsphere) and exciting at 315 nm 69 . The luminescence lifetime decay measurements were collected using a Horiba DeltaFlex Lifetime System equipped with a NanoLED N-330 nm LED ( λ ex  = 336 nm) and a 400 nm longpass filter.…”

Indium Phosphide‐Based Quantum Dots with Shell‐Enhanced Absorption for Luminescent Down‐Conversion

“…[43,44] The external quantum yield is defined as the ratio between the numbers of photons emitted by and incident on the phosphor layer, whereas the internal quantum yield is the ratio between the number of photons emitted and photons absorbed by the remote phosphor layer. Excitation of the samples was done with a blue LED (λ max of 446.5 nm, full width at half maximum of 19.2 nm and a luminous efficacy of 37 lm W -1 ) and detection of outgoing light by a CCD camera (Princeton Instruments ProEM 16002), attached to a spectrograph (Princeton Instruments Acton SP2358).…”