Luminescence Emission Research Articles

Photoactivated Circularly Polarized Room‐Temperature Phosphorescence from Phenoselenazine Derivative and Its Application in Information Security†

Comprehensive SummaryRoom‐temperature phosphorescence (RTP) materials have experienced rapid development due to their potential in organic light‐ emitting diode, information security, bioimaging, etc. However, the design of chiral organic phosphors with circularly polarized RTP (CPP) property remains a formidable challenge. Here, we introduce a chiral perturbation approach using a combination of chiral binaphthol and phenoselenazine derivative to achieve CPP. The photoactivated CPP in polystyrene (PS) film demonstrates a luminescence dissymmetry factor (glum), emission efficiency, and RTP lifetime up to 9.32 × 10–3, 27.0%, and 40.0 ms, respectively. The remarkable sensitivity of PS film to oxygen and temperature enables the adjustable emission colors, ranging from green to offwhite and blue under varying conditions. The doping systems, utilizing hosts of triphenylphosphine and 9‐phenylcarbazole, demonstrate an extended CPP lifetime of 85.9 ms and exhibit a persistent mechanoluminescence property with low pressure response threshold as low as 0.15 N. The information security provided by this CPP material was attained via the using of diverse emission colors and afterglow generated by distinct UV irradiation times and host materials. Alternately, it can also be achieved by observing different emission patterns using R‐ and L‐polarizer. The research has presented a reliable approach for producing CPP materials with high emission efficiency and glum.

Application of near-infrared-to-blue upconversion luminescence for the polymerization of resin cements through zirconia discs

ObjectivesTo investigate a near-infrared-to-blue luminescence upconversion curing method for polymerizing resin cements under zirconia discs. MethodsLava zirconia discs of different thicknesses (0.5–2.0 mm) were manufactured. First, the transmittances of the NIR and two blue lights (BLs) (LED and halogen lights) through these discs were measured. Second, NaYF4:Yb3+/Tm3+ upconversion phosphor (UP) powder was milled into 0.5-μm particle sizes. A light-curable resin cement VariolinkII base was chosen as the control (UP0), and an experimental cement (UP5) was prepared by adding 5 % UPs. These two cements were examined using multiphoton excitation microscopy for particle distribution. UP5 and UP0 were polymerized with or without zirconia shielding then subjected to a microhardness test. A multifold analysis was performed to examine the effects of zirconia thickness, curing protocols (pure BL or combined BL and NIR curing), and cement type. ResultsThe transmittance of NIR was superior to that of BL through zirconia discs of all thicknesses. UP particles were homogeneously distributed in UP5 and emitted blue luminescence under 980-nm NIR excitation. UP5 showed higher microhardness values than UP0 under any curing protocol or zirconia shielding condition. The combination of 20-s BL and 40-s NIR curing yielded the highest microhardness in uncovered UP5. However, combining 40-s BL and 20-s NIR curing surpassed the other groups when the zirconia discs were thicker than 0.5 mm. SignificanceNIR exhibits higher transmission through zirconia than BL. UP particles work as strengthen fillers and photosensitizers in cements. NIR upconversion curing could be a new strategy for polymerizing resin cements under thick zirconia restorations.

Circularly Polarized Electroluminescence from Intrinsically Axial Chiral Materials Based on Bidibenzo[b,d]furan/bidibenzo[b,d]thiophene

AbstractHerein, by connecting chiral bidibenzo[b,d]furan/bidibenzo[b,d]thiophene and multi‐resonance thermally activated delayed fluorescence (MR‐TADF) units, two pairs of intrinsically axial chiral MR‐TADF materials (R/S‐BDBF‐BNO and R/S‐BDBT‐BNO) realize mirror‐symmetric circularly polarized luminescence (CPL) and narrowband emission. The chiral moieties effectively engage in frontier molecular orbital distributions through the establishment of covalent bonds with boron atoms. The proportions of (1,1′‐bidibenzo[b,d]furan)‐2,2′‐diol in the highest occupied and lowest unoccupied natural transition orbitals (HONTO/LUNTO) are 25.3% and 64.7%, respectively. In addition, BDBT‐BNO processes a dual‐channel transition mode, thus the (1,1′‐bidibenzo[b,d]thiophene)‐2,2′‐diol constitutes 22.8%, 24.3% and 54.0%, 46.9% of the distributions of HONTO, HONTO‐1 and LUNTO, LUNTO+1, respectively. The high proportions endow R/S‐BDBF‐BNO and R/S‐BDBT‐BNO with good CPL properties with dissymmetry factors (|gPL|) of 1.7/1.8 × 10−3. Correspondingly, the circularly polarized organic light‐emitting diodes based on the enantiomers exhibit mirror symmetrical circularly polarized electroluminescence with |gEL| factors of 1.5/1.6 × 10−3. Furthermore, the introduction of sulphur atoms enables BDBT‐BNO to have a high maximum external quantum efficiency of 35.7% in device.

Perovskite oxide nanoparticles: Dual role as supports for luminescent Eu(III) ions and photocatalysts for bisphenol degradation

Perovskite oxides, such as CaTiO3, SrTiO3, and BaTiO3, have gained significant recognition for their dual role as luminescence supports and photocatalytic materials. In this study, we synthesized perovskite oxide nanoparticles (NPs) using the thermal calcination method and employed them as photocatalysts for the degradation of bisphenol S (BPS) and bisphenol AF (BPAF) under UVC irradiation. The as-synthesized photocatalysts were thoroughly examined for the photocatalytic degradation process and identified secondary products were identified using liquid chromatography in conjunction with high-resolution mass spectrometry. Our observations highlighted the relatively faster photocatalytic degradation of BPS compared to BPAF. Notably, among the perovskite oxide materials, SrTiO3 exhibited the highest catalytic activity for BPS degradation, while BaTiO3 outperformed in the case of BPAF degradation. Perovskite oxide NPs were also utilized as supports for doping with Eu3+ ions to create phosphor supports. Luminescent emissions from the Eu3+ ions, characterized by the 5D0 → 7FJ = 0-4 transitions, were observed and varied depending on the support material. Notably, Eu3+ doped in CaTiO3 nanoparticles exhibited the highest luminescence efficiency. These results highlight the dual functionality of perovskite oxide-based materials in phosphor applications and photocatalysis, offering valuable insights into their potential for both enhancing luminescence efficiency and treating bisphenols.

Ligand regulation strategy enhanced anodic electrochemiluminescence of copper nanoclusters for enrofloxacin trace determination

Copper nanoclusters (Cu NCs) have emerged as promising nano-emitters. However, their limited luminescence stability and emission intensity restrict their application in electrochemiluminescence (ECL). Herein, a ligand regulation strategy was developed to enhance the anodic ECL of Cu NCs. Specifically, we utilized ovalbumin (OVA), a naturally occurring protein, as a stabilizing ligand for the Cu NCs and introduced terbium ions into the ligand. This approach optimizes ECL performance by enhancing electron transfer efficiency and suppressing non-radiative relaxation. Additionally, we used the enhanced ECL nano-emitter as a signal probe and combined it with split aptamers to develop an analytical platform. This platform is designed for the detection of enrofloxacin (ENR) in food samples. The sensing platform incorporated a self-designed ENR test cell combined with 3D printing, ITO sputtering and screen-printing technologies, which greatly improved the reproducibility of the test results. Our study highlights the potential of this innovative detection method in the realm of food detection.

Combined TL and EPR study to elucidate the origin of luminescent emission from La-doped CaF2 phosphor

This paper presents the results of the combined study of the thermoluminescence (TL) and electron paramagnetic resonance (EPR) properties of La-doped CaF2 (CaF2: La) phosphor. X-ray diffraction (XRD) results confirmed that CaF2 has been successfully synthesized. Scanning electron microscopy (SEM) results and energy dispersive spectrometer (EDS) spectra show that the synthesized phosphor is pure and has a good overall morphology. The glow curve of CaF2: La phosphor shows an emission band between 230 and 500 nm centered at 340 nm. The Tm-Tstop method and the deconvolution technique were used to find the number of overlapping TL peaks in the 50–300 °C region and their kinetic parameters. A linear dose-response curve was obtained for the range 1–9 Gy, with the onset of a slight supralinear behavior for doses higher than 9 Gy. Gamma-irradiated CaF2: La phosphor has been studied using the technique of EPR to identify the defect centers and also to infer the centers involved in the TL process. Thermal annealing studies indicate the presence of three defect centers. One of the centers (center I) is identified as the O2− ion and is characterized by an axial g-tensor with principal values g∥ = 2.013 and g⊥ = 2.0053. This center correlates with the TL peak at 200 °C. Center II with an isotropic g-value of 2.0005 is attributed to an F center and also relates to the 200 °C TL peak. The third center (center III) is assigned to an F center.

Dual co-doping strategy for prolonged luminescence in laser-sintered BaAl2O4:Eu2+, RE3+ ceramics

This work reports on the influence of co-doping on the luminescence and persistent luminescence properties of BaAl2O4 (BaO·Al2O3) laser-sintered ceramics. The samples were doped with Eu and doubly co-doped with different rare earths (Dy, Er, Nd, Pr, and Tm) followed by laser-sintering without an atmospheric control, at a power density of 1.6 W/mm2. All sintered ceramics contained the hexagonal BaAl2O4 phase and had a homogeneous microstructure. A photoluminescence emission band centered at 495 nm was observed, which was due to the 4f65 d1 → 4f7 Eu2+ transition in the BaAl2O4 matrix. The persistent luminescence emission was monitored for 15 min after charging at 345 nm for 3 min. The combination of Nd and Dy co-doping led to substantial improvements in decay time and persistent luminescence intensity compared to individual co-doping. These results suggested that the two co-dopants interacted by modifying the trap configurations in the BaAl2O4 matrix.

IRSL properties of HfO2 obtained by the precipitation method and its correlation to ESR centres

Infrared-stimulated luminescence (IRSL) emission and its characterisation are reported for the first time for HfO2 synthesised by the precipitation method and its electron spin resonance (ESR) centres properties are shown in this study. IRSL spectrum has a broad emission band in the blue region, which is centred at about 2.49 eV. A similar emission was observed for the radiofluorescence (RF) with a band centred at 2.52 eV. RF signal intensity decreases with the readout temperature, which might indicate a thermal quenching process.IRSL signal is strongly affected by the readout temperature, as part of its emission is related to the presence of shallow traps (<100 °C). The IRSL shine-down curve is composed of two components with decay times of 15.7 and 800 s, and photoionisation cross-section values of about 1.20 × 10−19 and 2.35 × 10−21 cm2, respectively, based on IRSL carried out at 100 °C after 2 Gy of beta irradiation dose, using a general-order kinetic model. Dosimetric analyses indicated that there is a reproducible signal in IRSL, with a coefficient of variation lower than 9 % for repeatability and 3 % for reproducibility measurements. The dose-response curve has a linear trend in the dose range of 0.3–2.0 Gy. Regarding the photon energy study, it shows an overresponse for photo energy values below 200 keV. Fading of about 40 % after one day of storage was observed.Bleaching measurements indicated that the TL peaks located between 100 and 250 °C share the same trap levels as the IRSL ones. In addition, a possible charge transference is observed from the peak at 330 °C to lower temperature peaks. ESR analyses identified that oxygen vacancies of V+ type in a four-coordinated arrangement are induced by irradiation and are temperature-sensitive. Based on the bleaching and ESR measurements, it is reasonable to infer that V+ type vacancies are likely responsible for the IRSL, and its blue emission.

Synthesis of eco-friendly borosilicate glass with Eu3+ dopants: Harnessing recovered silica gel waste for reddish-orange emission materials

In this study, recovered silica gel waste (RSGW) is used as a key raw material to create borosilicate glass doped with Eu3+ ions in a new and environmentally friendly way. The glass compositions were fabricated using the melt quenching method, with different amounts of RSGW and a constant 1.0 mol% Eu3+ doping concentration. The study shows that increasing the doping concentration of RSGW improves the glass density and rigidity while reducing the molar volume, indicating enhanced glass stability. Photoluminescence and X-ray luminescence analyses confirm that the optimal composition with 50 mol% RSGW exhibits the strongest emission. Based on the phonon sideband analysis, the host glasses have a phonon energy of 966.53 cm− 1. An X-ray absorption near-edge structure (XANES) analysis showed that most of the europium ions were in the 3+ oxidation state. The CIE 1931 chromaticity investigation shows the x,y color coordinates at (0.645, 0.351) in the reddish-orange region. To optimize the doping concentration of Eu2O3, it was determined that a fixed concentration of 50 mol% RSGW created the most suitable mixture. Both luminescence emission spectra exhibit strong luminescence, with a peak emission wavelength of 615 nm (⁵D0→⁷F2), confirming concentration quenching in both photoluminescence and x-ray luminescence at a concentration of 1.0 mol%. The study explores potential applications of this novel material in photonics and suggests that this eco-friendly synthesis approach holds great promise for sustainable and efficient production of reddish-orange emission materials.

Two-Photon Nanoparticle Probe for Formaldehyde Detection via the AILE Luminescence Mechanism.

A two-photon nanoparticle probe was designed and developed based on the principle of intermolecular interaction of the aggregation-induced locally excited emission luminescence mechanism. The probe has the advantages of simple synthesis, convenient use, strong atomic economy, good biocompatibility, and photobleaching resistance. It can produce a specific and sensitive response to formaldehyde, help detect FA in normal cells and cancer cells, and is expected to become a specific detection probe for FA in vitro and in vivo.

Eu2+-Eu3+ Co-doping provoking polyhedron-cluster-based emission structural unit evolution triggering phases transition and blue-green-red multimode luminescence emission

A series of Ca2-xSiO4:xEu2+/Eu3+ and Ca2-2xSiO4:xEu2+/Eu3+, xM (M = Na+, K+) phosphors were prepared by co-doping Eu2+-Eu3+ in Ca2SiO4 solid solution for selectively locating Eu2+-Eu3+ ions deriving polyhedron-distorted emitting structure units’ evolution. During β, γ1,2-C2S matrix phase transitions, the structure and luminescence properties were analyzed by XRD, diffuse reflection, PL and luminescence thermal stability. The results show that Eu2+/Eu3+ occupying 6 Ca2+ sites forms 10 emission structural units in the matrix and the phase transition of γ1-Ca2-xSiO4(x = 0.0001–0.0004)→β-Ca2-xSiO4 (x = 0.0005–0.04)→β, γ2-Ca2-xSiO4 mixed phase (x = 0.08–0.32) is generated by the extrusion of structural units. Ultraviolet–visible diffuse reflectance spectra confirm the band gap difference caused by structural unit rotation. According to the bond energy method, the priority occupation order for the Eu2+/3+ ions was determined. The energy transfer of Eu2+→Eu3+ occurs when the structural units 3–10 of β, γ2-Ca2-xSiO4 mixtures coexist. After co-doped M+ as charge compensator, the luminescence intensity/thermal stability of Ca2-2xSiO4:xEu3+, xM(M = Na+, K+) were improved by 33.88 %/57.12 %, and 5.1 %/6.6 % than that of Ca2-xSiO4:xEu3+, respectively. These characteristics indicate that phosphors have broad application prospects in the field of solid-state lighting.

Effect of ZnO on Luminescence Performance of Terbium-Activated Zinc Borosilicate Glasses.

In this study, terbium-doped ZnO-SiO2-B2O3-Na2O glasses were fabricated with the conventional melt-quenching method. The effect of altering the concentration of the host matrix on luminescence performance was investigated in terms of different ZnO/B2O3 and ZnO/SiO2 ratios. FT-IR results indicate that bridging oxygens (Bos) were converted to non-bridging oxygens (NBOs) with increments of ZnO. Furthermore, the emission intensity and luminescence lifetime of samples were influenced by the amount of ZnO; this was proven with photoluminescence spectra results. The maximum emission intensity was observed at a 1.1 ZnO/B2O3 ratio and a 0.8 ZnO/SiO2 ratio; however, the highest luminescence lifetime was observed at a 1.1 ZnO/SiO2 ratio. The emission intensity and luminescence lifetime of glass samples were improved by heat treatment as a result of the formation of willemite and zinc oxide phases. An increase in the ZnO/SiO2 ratio facilitated the formation of willemite and zinc oxide phases; therefore, crystallinity was directly related to the luminescence behavior of glass samples.

Luminescence and two-photon absorption assisted optical limiting properties of Ag-doped CdWO4 nanorods

The emerging demand for the fabrication of nonlinear optical materials with high limits of optical power is obvious in nonlinear optics due to their wide application in photonic devices. We report the linear and third-order nonlinear optical properties of Ag-doped CdWO4 nanorods and their dependence on Ag-doping concentration. CdWO4 nanorods with different Ag concentrations were synthesized by the chemical precipitation method and characterized by UV–Vis absorption, X-ray diffraction (XRD), Raman, Photoluminescence and its lifetime studies, X-ray Photoelectron spectroscopy and Transmission Electron Microscopy (TEM). The introduction of Ag ions has led to an increased redshift in the CdWO4 absorption spectra extended into longer wavelength bands, thus enhancing optical absorption within the visible range. The XRD pattern showed that the nanorods crystallized in a monoclinic wolframite structure. The incorporation of Ag in CdWO4 decreases the luminescence emission intensity due to surface quenching effect. Luminescence lifetime measurement reveals the longer decay lifetime for Ag-doped CdWO4 nanorods due to the reduction of density of defects and deep trap state. The nonlinear optical behaviour of the nanorods was investigated by an Open aperture Z-scan technique at 532 nm using pulsed wave Nd: YAG laser. Experimental results showed that reverse saturable absorption is responsible for the observed nonlinearity in the nanorods. The addition of Ag can significantly improve the nonlinear absorption coefficient and optical limiting effects of CdWO4 which can be used as a potential material in nonlinear optical devices.

Enhancing luminescence of AF2: Ln3+ (A = Ca, Sr; Ln = Eu, Tb) by the use of carbon dots

Lanthanide ions-doped fluoride nanocrystals have excellent application prospect. However, low photoluminescence quantum yield (PLQY) is usually along with lanthanide ions-doped fluoride nanocrystals owing to their low molar absorptivity and narrow absorption band. In order to increase the absorption cross section of Ln3+ in fluoride nanocrystals, a facile synthesis strategy to enhance luminescence of AF2: Ln3+ (A = Ca, Sr; Ln = Eu, Tb) by the use of carbon dots (CDs) has been developed in this work. A series of characterizations including TEM, XRD, FTIR and XPS demonstrated that the CDs have been successfully combined with the surface of AF2: Ln3+ nanocrystals. The combination of CDs has little influence on the microstructure and phase structure of AF2: Ln3+, and CDs@AF2: Ln3+ nanocrystals have uniform and regular shape with cubic phase. CDs are used as a broadband sensitizer and lead to the broadband excitation of Ln3+, resulting in the enhancement around 10-fold of Ln3+ luminescence emission in AF2: Ln3+ nanocrystals after CDs combination. The corresponding PLQY increases almost three times, and the luminescence enhancement mechanism by combining CDs is proposed. In addition, the CDs@AF2: Ln3+ nanocrystals are used to prepare CDs@AF2: Ln3+/PVA films, which exhibits excellent luminescence properties under the excitation of UV light. This work provides a superior method for enhancing the luminescence properties of lanthanide ions-doped nanocomposites and demonstrates practical potential as promising candidates for light-converting thin films.

Rapid and reliable ratiometric fluorescence detection of isoquercitrin based on a high-nuclearity Zn(II)-Nd(III) nanomolecular sensor

Rapid and quantitative detection of isoquercitrin (Isq) has been attracting much attention due to its outstanding pharmacological and physiological activities. Herein, an interesting 48-metal Zn(II)-Nd(III) nanocluster (1, molecular sizes 1.3 × 2.8 × 3.1 nm) with salen-type Schiff base ligand was constructed as molecular sensor for the luminescence detection of Isq. 1 exhibits visible ligand-centered emission and NIR luminescence of Nd(III), and shows ratiometric fluorescence response to Isq with high sensitivity even in the presence of other interferences. The fluorescence sensing behavior can be expressed by a second-order equation I1060nm/I480nm = A*[Isq]2 + B*[Isq] + C, which is used to quantitatively analyze the Isq concentrations in DMF and FCS. The LODs to Isq for the ligand-centered and lanthanide emissions of 1 in DMF are 0.21 μM and 0.11 nM, respectively. The quenching of the ligand-centered emission of 1 caused by Isq is attributed to the competitive absorption of light energy and “inner effect”, while, the luminescence enhancement is due to the “antenna effect”.

Dual-functional fluorescence sensors based on 3D lanthanide metal–organic framework and its mixed matrix membrane

A new lanthanide metal–organic framework (Ln-MOF) {[Eu(DPB)(H2O)](Me2NH2+)}n (1) (H4DPB = (1,1′:3′,1′’-terphenyl)-3,3′’,5,5′’-tetracarboxylic acid）was synthesized under solvothermal conditions and presented a fascinating three-dimensional (3D) framework with 4,8-connected diamond topology, which were built from Eu3+ ions and tetra carboxylate groups. 1 showed strong red luminescence emission in the solid state at room temperature and exhibited good stability in different solvents. 1 could be used as a multi-responsive luminescent sensor for hemin and p-Nitrophenol (4-NP) with detection limits of 3.91 × 10−6 M and 1.98 × 10−4 mM, respectively. Moreover, using 1 as a filler and poly (vinylidene difluoride) (PVDF) as matrix, a mixed matrix membrane 1@PVDF was successfully prepared. 1@PVDF also exhibited fluorescence emission comparable to that of 1 and could be used for hemin and 4-NP sensing with good selectivity and remarkable recyclability.

Decomposition of Luminescent Hydroxyapatite Scaffolds in Simulated Body Fluid.

We present a luminescence study investigating the dissolution of rare-earth-doped hydroxyapatite scaffolds in simulated body fluid (SBF), aiming to assess the luminescence stability of Tb-, Ce-, and Eu-doped scaffolds over time. Our findings reveal a consistent decrease in luminescence emission intensity across all samples over a four-week period in which the scaffolds were immersed in the SBF. In addition, energy-dispersive spectroscopy confirms a decrease in rare-earth ion concentration in the scaffolds with respect to time, whereas fluorescence spectroscopy shows the presence of rare-earth ions in the SBF, indicating the partial dissolution of the scaffolds over time. The use of rare-earth ions as luminescence markers provides insights into the mechanisms of apatite formation in hydroxyapatites. Thus, these scaffolds may find wider use in regenerative medicine, particularly in targeted drug delivery systems, where their luminescent properties have the potential to noninvasively track drug release.

Silver Dendritic Gels with Luminescence and Aggregation-Induced Emission Effect.

This work reports on a novel family of silver metallogels based on discrete coordination complexes. Structurally, they consist of dendrimers containing a trinuclear silver metallacycle at the core, with the general formula [M(μ-pz)]3, and poly(benzyl)ether branched structures with different numbers or terminal alkoxy chains at the periphery. These silver metallodendrimers are able to gel low-polarity solvents such as dodecane or cyclohexane, giving rise to luminescent organogels at room temperature with the property of aggregation-induced emission (AIE). This property means that in solution or the sol state, they are weak emitters, but in the gel state, luminescence is considerably increased. In this particular case, they exhibit blue luminescence. Two different dendritic scaffolds have been studied, finding significant differences in solubility, gel formation and dependence of luminescence on temperature. The results show that properly tailored silver gelators can show luminescence in the gel state.

Synthesis, characterization, crystal structures and photophysical properties of pillar-layer nickel metal-organic frameworks based on 2-aminoterepthalic acid and 5-aminoisopthalic acid

Five new compounds, [Ni2(2-NH2BDC)2(bipy)2(H2O)4](1), [Ni(5-aip)(phen)(H2O)3].2H2O (2), [Ni4(5-aip)3(bipy)3(H2O)7]. 19H2O (3), [Ni(5-aip)(bipy)(H2O)]n·2H2ODMF (4), and [Ni2(2-NH2BDC)2(phen)2(H2O)4](5) based on 5-aminoisophthalic acid and 2-aminoterepthalic acid, have been synthesized at room temperature using methanol and water solvent mixture and structurally determined using single crystal X-ray diffraction.Compounds 1–3 are discret complex while compound 4 shows two-dimensional (2D) pillar-layer architecture. In all these compounds, channels are observed through CH···O interactions between adjacent molecules. Compounds 1–5 displayed one broad emission band with a center at 384 nm when excited 294 nm in their solid state at room temperature, attributed to ligand-to-metal charge transfer. In comparison with emission peaks of 5-aminoisophthalic acid and 2-aminoterepthalic acid, the luminescent emissions of these compounds are blue-shifted due to a decrease of the energy gap between the ground and excited states in the ligand upon complexation with Ni(II).

Do attenuation coefficients based on luminescence bleaching fronts reflect true light attenuation in rocks?

The emerging technique of rock surface luminescence dating employs a double-exponential fitting dating model based on the Bouguer-Lambert law. The accuracy of exposure age determination is sensitive to the light attenuation coefficient, μ, which is usually derived from fitting the luminescence profile as a function of depth into the rock. Alternatively, μ might be determined by direct measurement using a spectrophotometer. However, their directly measured values of μ were significantly larger than those estimated from field luminescence bleaching data. Here, we aim to confirm these previous results by measuring the luminescence-depth profiles of both IRSL and IRPL signals from granite rock exposed to different light sources, including sunlight, SOL2 and IR LEDs under controlled conditions. We also measured monochromatic light (blue LED: (470 ± 30) nm, green LED: (520 ± 30) nm, and infrared LED: (850 ± 30) nm) attenuation in granite rock slices of varying thickness (0.62–2.60 mm) using a high-sensitivity photodiode. Finally, we use a camera-based measurement system and a Risø Luminescence Imager to investigate spatial variation in transmitted light as a function of slice thickness. The spatial correlation between direct light transmission and luminescence emission is then investigated, to investigate the underlying reasons for the difference between direct measurement and luminescence-based estimates of μ. We find that light attenuation through a granite rock slice is very heterogeneous; most light penetrates through localized low attenuation light paths corresponding to transmission through the most transparent grains, presumably quartz. The light penetration and escape into the surrounding matrix are assumed to be influenced by the surface area of quartz grains. As a result, transmissive light paths result in a significant area of feldspar grains at depth in the slice being exposed to more light than might be expected from average attenuation measurement. When the incident light predominantly travels through feldspar minerals, simultaneously stimulating luminescence from within any potassium feldspar (K-feldspar), the attenuation coefficients derived from the luminescence-depth profiles tend to be smaller than the average of 1.18 ± 0.07 (n = 79) irrespective of the kinetic model used for fitting. Thus, luminescence-based attenuation coefficient estimates appear to be affected by the distribution of light attenuation across and within the rock slice, making such estimates preferable to directly measured (average) estimates of light attenuation coefficients. These insights are important for our understanding of the significance of light attenuation coefficients in rock samples; they contribute to the reassessment of parameters and measurement methods in dating models and so to improvements in accuracy of rock surface luminescence dating techniques.