Photoluminescence Imaging Research Articles

Controllable growth of Ga2O3 hexagonal prism with pyramid end and monitoring size-dependent electron transfer process in perylene/Ga2O3 conjugate system via FLIM

Hexagonal prisms with hexagonal pyramid end of Ga2O3 microstructures were successfully prepared on gallium arsenide substrate by double cell electrochemical etching method under various growth conditions. The field emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy (XPS), photoluminescence (PL) and fluorescence lifetime imaging microscopy (FLIM) were used to characterize the hexagonal prisms. The EDS analysis confirmed that the prepared prisms were composed dominantly of gallium (Ga) and oxygen (O) with atomic ratio of ~ 2:3. The binding energy of the Ga 2p and Ga 3d XPS peaks revealed that the formation of Ga–O bonding with the highest oxidation state of Ga (Ga3+) and the formed hexagonal microstructures were Ga2O3. The PL spectra at room temperature under excitation at 290 nm exhibit a strong blue emission peak located at about 470 nm. The origin of this PL peak can be attributed to exciton recombination at different intrinsic defect sites such as O vacancies and Ga vacancies. Moreover, FLIM technique has been employed to probe time-resolved photoluminescence properties of individual Ga2O3 prisms with hexagonal tip. FLIM images provide two-dimensional spatial maps of the carrier recombination lifetime which considered the most critical parameter to improve the performance of optoelectronic devices. It has been concluded that the carrier recombination lifetime was strongly sensitive to the size of the hexagonal prism-shaped structures due to surface-related defects. Additionally, a quantitative analysis of a conjugate system prepared by functionalizing hexagonal Ga2O3 prisms with perylene organic dye molecules was reported in this work. The size-dependent electronic coupling between the conduction band level of gallium oxide and excited states of perylene molecules was investigated. We observed that highly efficient electron transfer process occurs for aggregated molecules due to excimer trap states. The grown prism structures seem to be interesting for applications in optoelectronic devices as well as to be used as an effective host medium for organic dye molecules in solar cell applications.

Photoluminescence Analysis of Individual Partial Dislocations in 4H-SiC Epilayers

Configurations of the basal plane dislocations in 4H-SiC epitaxial layers are classified into two types, having typical combinations of ‘straight Si-core and straight C-core’ and ‘straight Si-core and curved C-core’ partial dislocations. The core species are determined by the photoluminescence images and observation of the moving Si-core partial dislocations by ultra-violet light illumination. Each partial dislocation was analyzed by photoluminescence spectroscopy. As the results, C-core partial dislocations have been found to have different peak wavelengths depending on the excitation power of the illumination. Also from the detailed analysis of individual partial dislocations, the curved C-core partial dislocations have been found to have different characters which may be originated from the mixture of different types of dislocations. It has been suggested that this model is possibly described by continuous connection of 30o and 90o dislocations which have different configurations of dangling bonds. The difference in photoluminescence peak wavelength might be explained by the structural difference.

Anomalous dislocation annihilation behavior observed in a GaN crystal grown on point seeds by the Na-flux method

We recently invented a method called the flux-film-coated technique for purifying a GaN wafer with low dislocation density grown from point-seed crystals. In this study, we investigated the mechanism behind the reduction of dislocation density in the GaN wafer by evaluating the three-dimensional behavior of dislocations using multiphoton-excitation photoluminescence images. We made the surprising discovery that dislocations more than 50 μm away disappeared by annihilating each other as growth proceeded, and this is one of the mechanisms underlying the dislocation density reduction. The moving distance of dislocations before annihilation is uncommon and a unique phenomenon in the Na-flux method.

Dark Lock-in Thermography Identifies Solder Bond Failure as the Root Cause of Series Resistance Increase in Fielded Solar Modules

Correlating the electrical performance of photovoltaic modules to the spatially resolved photoluminescence, electroluminescence, and dark lock-in thermography (DLIT) images is an important long-term goal for developing solar cell technology. These images offer highly sophisticated and detailed information about the spatial distribution and (if imaged at successive time intervals) temporal degradation of local series and shunt resistances. There have been extensive studies to correlate these imaging techniques to local characteristics at the cell level. However, it has been difficult to extract and quantify module-level information from the techniques. In this study, we interpret module current-voltage (I-V) measurements along with corresponding DLIT images within a module-scale simulation framework, demonstrating that series resistance degradation of the module I-V characteristics, in this case, can be attributed to solder bond failures. Our simulations highlight how current crowding associated with a failed solder joint (or a section of the solder pad) translates to the characteristic point-like (asymmetric doublet) heating pattern in neighboring solder joints (or the neighboring regions of the solder pad). The correlation between series resistance and solder joint degradation could inform expedited diagnosis of field degradation of solar modules.

Informative Aspects of Molten KOH Etch Pits Formed at Basal Plane Dislocations on the Surface of 4H‐SiC

Despite being a destructive technique, molten KOH etch pits at basal plane dislocations are found to have informative aspects, as revealed by photoluminescence imaging and optical microscopy, on the 4° off‐cut (0001) surface of 4H‐SiC p–i–n diode chips, where single Shockley‐type stacking faults have expanded during electroluminescence experiments. Smaller etch pits are observed aligning on single lines along ±[100] that are the shallowest sides of stacking faults. Through closer observation of the pits, the facing directions are found to agree well with a model explaining the two types of partial dislocations constituting the line. Other basal plane dislocation pits are observed by scanning electron microscopy on the sublimation‐grown wafer surface before epitaxial growth. The distances between the partial dislocation cores are measured at each pit. No basal plane dislocation etch pit facing toward ±[100] is found, but a weak correlation is noted between the partial dislocation distance at the cores and the direction that the basal plane dislocations face. The corresponding results are discussed in terms of the image force and the force exerted on steps perpendicular to the (0001) plane, to understand the mechanisms of basal plane dislocation propagation and/or conversion to threading edge dislocations.

Laser-Induced Periodic Ag Surface Structure with Au Nanorods Plasmonic Nanocavity Metasurface for Strong Enhancement of Adenosine Nucleotide Label-Free Photoluminescence Imaging.

The label-free detection of biomolecules by means of fluorescence spectroscopy and imaging is topical. The developed surface-enhanced fluorescence technique has been applied to achieve progress in the label-free detection of biomolecules including deoxyribonucleic acid (DNA) bases. In this study, the effect of a strong enhancement of photoluminescence of 5′-deoxyadenosine-monophosphate (dAMP) by the plasmonic nanocavity metasurface composed of the silver femtosecond laser-induced periodic surface structure (LIPSS) and gold nanorods or nanospheres has been realized at room temperature. The highest value of 1220 for dAMP on the Ag-LIPSS/Au nanorod metasurface has been explained to be a result of the synergetic effect of the generation of hot spots near the sharp edges of LIPSS and Au nanorod tips together with the excitation of collective gap mode of the cavity due to strong near-field plasmonic coupling. A stronger plasmonic enhancement of the phosphorescence compared to the fluorescence is achieved due to a greater overlap of the phosphorescence spectrum with the surface plasmon spectral region. The photoluminescence imaging of dAMP on the metasurfaces shows a high intensity in the blue range. The comparison of Ag-LIPSS/Au nanorod and Ag-LIPSS/Au-nanosphere metasurfaces shows a considerably higher enhancement for the metasurface containing Au nanorods. Thus, the hybrid cavity metasurfaces containing metal LIPSS and nonspherical metal nanoparticles with sharp edges are promising for high-sensitive label-free detection and imaging of biomolecules at room temperature.

Photoluminescence of CVD-grown MoS2 modified by pH under aqueous solutions toward potential biological sensing

Transition metal dichalcogenide (TMD) represented by molybdenum disulfide (MoS2) is a promising platform for versatile applications in biosensing. The semiconducting properties of MoS2 coupled with its large surface area allows for highly sensitive detection of external environments. Although chemical vapor deposition (CVD) is a promising method for synthesizing large and high quality MoS2, optical properties of CVD-grown MoS2 under physiological solution is not clear. Furthermore, understanding of the pH effect on its optical properties is still limited.Here, we report their photoluminescence (PL) responses to solution pH under aqueous condition by means of PL spectroscopy and imaging. MoS2 with different Mo sources and additive such as MoS2, MoO2 and NaCl were synthesized. It was found that the PL response was highly affected by the Mo sources. While MoS2 made from MoO2 showed the highest modulation of PL by solution pH, MoS2 made from MoS2 did not show significant response. Furthermore, we demonstrated enhanced pH-sensitivity by UV/O3 treatments. Spectral analysis on PL and x-ray photoelectron spectroscopy revealed that the PL responses to solution pH were not directly correlated to the defect density (S/Mo ratio) of MoS2, but likely correlated to its state of defects and initial carrier density. These findings will be a practical guideline to optimize synthesis condition toward developing MoS2-based optoelectronic biosensing devices.

Large area chemical vapour deposition grown transition metal dichalcogenide monolayers automatically characterized through photoluminescence imaging

Chemical vapour deposition (CVD) growth is capable of producing multiple single-crystal islands of atomically thin transition metal dichalcogenides (TMDs) over large areas. Subsequent merging of perfectly epitaxial domains can lead to single-crystal monolayer sheets, a step towards scalable production of high quality TMDs. For CVD growth to be effectively harnessed for such production it is necessary to be able to rapidly assess the quality of material across entire large area substrates. To date, characterisation has been limited to sub-0.1-mm2 areas, where the properties measured are not necessarily representative of an entire sample. Here, we apply photoluminescence (PL) imaging and computer vision techniques to create an automated analysis for large area samples of monolayer TMDs, measuring the properties of island size, density of islands, relative PL intensity and homogeneity, and orientation of triangular domains. The analysis is applied to ×20 magnification optical microscopy images that completely map samples of WSe2 on hBN, 5.0 mm × 5.0 mm in size, and MoSe2–WS2 on SiO2/Si, 11.2 mm × 5.8 mm in size. Two prevailing orientations of epitaxial growth were observed in WSe2 grown on hBN and four predominant orientations were observed in MoSe2, initially grown on c-plane sapphire. The proposed analysis will greatly reduce the time needed to study freshly synthesised material over large area substrates and provide feedback to optimise growth conditions, advancing techniques to produce high quality TMD monolayer sheets for commercial applications.

Benign ferroelastic twin boundaries in halide perovskites for charge carrier transport and recombination

Grain boundaries have been established to impact charge transport, recombination and thus the power conversion efficiency of metal halide perovskite thin film solar cells. As a special category of grain boundaries, ferroelastic twin boundaries have been recently discovered to exist in both CH3NH3PbI3 thin films and single crystals. However, their impact on the carrier transport and recombination in perovskites remains unexplored. Here, using the scanning photocurrent microscopy, we find that twin boundaries have negligible influence on the carrier transport across them. Photoluminescence (PL) imaging and the spatial-resolved PL intensity and lifetime scanning confirm the electronically benign nature of the twin boundaries, in striking contrast to regular grain boundaries which block the carrier transport and behave as the non-radiative recombination centers. Finally, the twin-boundary areas are found still easier to degrade than grain interior.

(Invited) Exploring in the Near Infrared: Multifunctional Nanoplatforms for Biomedical Applications

Near-infrared (NIR) absorbing and emitting nanomaterials attract significant attention in bioimaging, which shows great potential for disease detection due to its high sensitivity at the subcellular level and low cost of related imaging facilities. However, currently available optical probes are mainly based on visible-emitting materials. The tissue-induced optical extinction and autofluorescence in the visible range result in limited penetration depth and ambiguous photoluminescence signal, which restricts their in vivo use. To address this issue, photoluminescent probes, with both absorption and emission wavelengths operating in the biological windows in the NIR range, in which tissues are optically transparent, are highly desired. Their integration with superparamagnetic nanomaterials to make a multifunctional platform further opens a wide range of promising applications, including bimodal imaging (photoluminescence and magnetic resonance imaging), synergistic hyperthermia (magnetothermal and photothermal), magnetic confinement of trace amounts of biospecies for ultra high-sensitivity biodetection, etc. In this talk, I will present our most recent work on the synthesis of NIR-emitting water soluble, stable core/shell/shell quantum dots (QDs) and multifunctional (NIR photoluminescent and superparamagnetic) nanoparticles and their use in biomedicine. For instance, in one case, multifunctional particles contain single superparamagnetic nanoparticles as cores and NIR-luminescent nanomaterials as shells. In another case, the multifunctional nanoplatform is compose of multiple superparamagnetic nanoparticles and NIR quantum dots in single particles. These different types of multifunctional particles are designed for different biomedical applications.

(Invited) Germanium Nanocrystal Luminescence: Spectral and Spatial Variations

Silicon-compatible germanium (Ge) coherent light sources have received considerable attention recently resulting in both lasing and photoluminescence (PL) in strained Ge, for which sufficient tensile strain reduces the relatively small indirect to direct bandgap (BG) difference to zero, thus making Ge a direct gap material, albeit at a relatively low energy. Previously we explained the cause of the intense, low temperature PL observed for many MBE-grown Si1-xGex epitaxial layers as being due to nm-thick Ge nanocrystals (NCs) embedded in the SiGe epilayers, as in the plan-view TEM image and schematic insets of Fig. 1. We showed that the Ge NC peak PL energy depends on several factors, namely: (a) Ge bandgap variation with vertical strain; (b) effect of the Ge-fraction in the host SiGe epilayer on the vertical lattice constant; (c) effect of strain on the SiGe bandgap energy; (d) confinement shifts in the Ge NCs; and (e) confinement shifts in the SiGe epilayers. A model incorporating these effects was developed that effectively explained the PL energy dependence for the SiGe samples comprising over 60 separate epilayer configurations (Fig. 1). The experimental data is presented in Fig. 1, which also contains on the left the PL spectra for three Ge NC samples, including the one to be discussed later in this paper. From the analysis of the data we were able to use confinement for the vertical size of the Ge NCs, which increased linearly with vertical tensile strain.Many of the Ge NC samples exhibited a very bright luminescence, with as high as 3% internal quantum efficiency. For one of the samples the PL was imaged in video format for broad band radiation from 1200 to 1900 nm. One such image is displayed in Fig. 2 for a sample at low temperature comprised of a SiGe/Si multiple quantum well (MQW) structure, with 40 epilayers of 7.6 nm thick Si0.75Ge0.25 separated by 20 nm of Si on a Si(001) substrate. In this case the excitation (100 mW at 514.5 nm in a 1 mm diameter beam) at normal incidence was at the center of the 3 mm diameter sample mask aperture. The exciting radiation was excluded from the camera aperture with a long-wave pass filter, which absorbed light with wavelengths below 1200 nm. On the right of the sample mask in the image, the sample extends with its (110) cleaved edge sticking out at a small angle (~20o) with respect to the edge of the sample mask. The PL is apparently brightest at the point of excitation, but is also quite intense at the edge of the sample, more so at the right hand edge. The trace below the image is the PL intensity profile along the thin yellow line, which indicates an intensity at the edge of the sample comparable to that at the excitation location. In this experiment the incident excitation light was polarized roughly parallel to the wafer edge.In the sample imaged, the MQW system is thick enough and has a high enough effective refractive index to act as a thin film waveguide in the infrared, which could account for much of the edge brightening in Fig. 2. In addition to the waveguiding in the thin film structure, we expect some bulk waveguiding in the silicon substrate, as the back surface is likely smooth enough and the silicon material is transparent in this wavelength range. The luminescence along the sample edge was brightest perpendicular to the excitation polarization, like fluorescence anisotropy. A broadband PL image is shown in Fig. 3 for the excitation focused to a 0.1 mm spot near the edge of the sample, where there a second bright PL spot. Two PL intensity profiles are shown, one through the excitation and edge spots and one along the wafer edge. We see that the edge brightening has also occurred, although the overall PL intensity is not so greatly increased on focusing, possible due to NC saturation effects possible when more than one exciton is captured by a Ge NC. However, we see from Fig. 3 that the edge emission is in a spot not greatly larger than the extent of the emission at the excitation spot. This observation suggests that the emission is quite collimated in the MQW waveguide, much more so than would be expected from the simple direction effects based on excitation-emission polarization that are normally seen for bulk luminescence. This lack of divergence between the excitation and the edge might be indicative of an optical amplification process occurring in the MQW waveguide. Figure 1

Application of photoluminescence microspectroscopy: a study on transfer of uranyl and europium ions on dry silica gel plate

ABSTRACT When water contacts with porous materials, water and chemical species dissolved in the water transfer into the inside of the porous materials. Here, to study the transfer of uranyl and europium ions on a dry silica gel plate, we dropped a small amount of aqueous solution (~0.5 μL) dissolving the two ions on a dry silica gel plate, and the distributions of the two ions spread on the silica gel plate were observed by photoluminescence microspectroscopy. Photoluminescence images of uranyl and europium ions clearly show that when uranyl ion coexists in the solution, europium ion transfers in a larger area compared to uranyl ion. It can be interpreted that the larger-area distribution of europium ion is caused because uranyl ion is preferentially adsorbed to silica gel and the uranyl adsorption disturbs the adsorption of europium ion. The coexistence of uranyl ion may influence the mobility of other ion species.

(Invited) Effect of the Plasma Etching on InAsP/InP Quantum Well Structures Measured through Low Temperature Micro-Photoluminescence and Cathodoluminescence

Photoluminescence and cathodoluminescence spectral imaging were performed across rectangular stripes etched in samples with InAsxP1-x quantum wells of constant thickness and variable composition grown on InP. In particular, the effects of different etching chemistries (CH4/H2/Ar and Cl2/CH4/Ar) were investigated. The results discussed deal with modifications of the luminescence line shapes (which differ with etching process) and with the intensity variation of the emissions associated with the quantum wells across the stripes. The possible origins of these effects are investigated in terms of carrier recombination on the vertical sidewalls of the stripes and lateral diffusion of species from the plasma during etching. Cathodoluminescence measurements on samples under DC-bias also show the quantum confined Stark effect which is correlated to the material modifications induced by the etching.

Triangular Single Shockley Stacking Fault Analyses on 4H-SiC PiN Diode with Forward Voltage Degradation

The structure of partial dislocations (PDs), which surround triangular single Shockley stacking faults (1SSFs) expanded during electroluminescence observation in a 4H-SiC PiN diode, is investigated by photoluminescence (PL) imaging, PL spectroscopy, plan-view transmission electron microscopy (TEM) imaging, g·b analysis, cross-sectional bright-field scanning TEM (BF-STEM) imaging, and high-resolution high-angle annular dark-field (HAADF)-STEM imaging. The zigzag configuration is found on the upstanding side of the triangular 1SSF by plan-view TEM imaging, while it is observed as a single line by PL imaging. Using g·b analysis, the zigzag line is confirmed to be constructed by 30° and 90° PDs. Cross-sectional BF-STEM observation proved that the expanding 1SSF penetrates through the p–n interface whose position was estimated from secondary-ion mass spectrometry (SIMS) depth profile measurements of the aluminum and nitrogen concentrations. This provides experimental evidence that the 1SSF loses its driving force for recombination-enhanced dislocation glide when it stops somewhere in the p-layer where sufficient electrons no longer exist. Using cross-sectional HAADF-STEM observation, core species of the PDs were analyzed and the Burgers vector for the dislocation loop uniquely determined. Also, the first experimental observation of a 90° silicon-core PD, reported so far, is confirmed. According to these PD analyses, the possible atomic arrangement around the 1SSF is examined and the way tetrahedrons face across each PD is summarized, based on HAADF-STEM analysis of the 1SSF line.

Improved silicon surface passivation by hybrid composites formed by PEDOT:PSS with anatase TiO2 nanoparticles

In this work, hybrid composites formed by PEDOT:PSS (poly(3,4-ethylene dioxythiophene):-polystyrene sulfonate) and anatase TiO2 nanoparticles synthesized by hydrolysis were spin-coated on Si substrates in order to evaluate their potential implementation in Si-hybrid solar cells, based on their passivation behaviour. X-ray diffraction (XRD), photoluminescence (PL), Raman spectroscopy, quasi-steady state photoconductance (QSS-PC) based on PL imaging, and Hall effect measurements were carried out for the structural, optical and electrical characterization. Enhanced carrier lifetime values of τ ~ 0.5 ms were obtained by adding a controlled amount of TiO2 nanoparticles (0.5% wt.) to the PEDOT:PSS matrix.

Role of PCBM in the Suppression of Hysteresis in Perovskite Solar Cells

AbstractThe power conversion efficiency of inorganic–organic hybrid lead halide perovskite solar cells (PSCs) is approaching that of those made from single crystalline silicon; however, they still experience problems such as hysteresis and photo/electrical‐field‐induced degradation. Evidences consistently show that ionic migration is critical for these detrimental behaviors, but direct in‐situ studies are still lacking to elucidate the respective kinetics. Three different PSCs incorporating phenyl‐C61‐butyric acid methyl ester (PCBM) and a polymerized form (PPCBM) is fabricated to clarify the function of fullerenes towards ionic migration in perovskites: 1) single perovskite layer, 2) perovskite/PCBM bilayer, 3) perovskite/PPCBM bilayer, where the fullerene molecules are covalently linked to a polymer backbone impeding fullerene inter‐diffusion. By employing wide‐field photoluminescence imaging microscopy, the migration of iodine ions/vacancies under an external electrical field is studied. The polymerized PPCBM layer barely suppresses ionic migration, whereas PCBM readily does. Temperature‐dependent chronoamperometric measurements demonstrate the reduction of activation energy with the aid of PCBM and X‐ray photoemission spectroscopy (XPS) measurements show that PCBM molecules are viable to diffuse into the perovskite layer and passivate iodine related defects. This passivation significantly reduces iodine ions/vacancies, leading to a reduction of built‐in field modulation and interfacial barriers.

Highly luminescent and stable CH3NH3PbBr3 quantum dots with 91.7% photoluminescence quantum yield: Role of guanidinium bromide dopants

Abstract Although perovskite quantum dots (PQDs) have received considerable attention, defects in PQDs can significantly degrade the properties and device performance. In this study, we report on an effective strategy for synthesizing highly luminescent CH3NH3PbBr3 quantum dots (QDs) by a simple doping. To remove such defects, guanidinium bromide (GuBr) was doped into the CH3NH3PbBr3 QDs synthesized by the ligand-assisted reprecipitation technique. From XRD and TEM studies, the doping of GuBr into the QD lattices was verified. In addition, the surfaces of PQDs with and without GuBr dopants were analyzed by XPS to trace the metallic Pb acting as a major recombination center. The GuBr doping resulted in the size uniformity of QDs and effectively eliminated defects and metallic Pb, which enhanced the photoluminescence quantum yield (PLQY) through the inhibition of the non-radiative recombination pathway. Furthermore, the recombination dynamics in the QDs were examined by using time-resolved photoluminescence and fluorescence lifetime imaging to verify the role of GuBr dopants. By optimizing the amount of GuBr doping, the CH3NH3PbBr3 QDs with strong green emission achieved a maximum PLQY of 91.7%.

Behavior of Threading Dislocations from GaN Substrate to Epitaxial Layer

Threading dislocations (TDs) in the GaN homoepitaxial layer were nondestructively evaluated using X-ray topography, Raman spectroscopy, and multi-photon photoluminescence imaging. TDs in the GaN substrate have been identified as threading edge dislocations (TEDs), threading mixed dislocations (TMDs), and threading screw dislocations (TSDs). In article number 1900527, Hisashi Yamada and co-workers discuss the direction and angle of inclined TDs in the GaN epitaxial layer. Stress relaxation via misfit dislocation is considered as a possible explanation for TED tilting toward the extra half plane.

Fully convolutional networks for chip-wise defect detection employing photoluminescence images

Efficient quality control is inevitable in the manufacturing of light-emitting diodes (LEDs). Because defective LED chips may be traced back to different causes, a time and cost-intensive electrical and optical contact measurement is employed. Fast photoluminescence measurements, on the other hand, are commonly used to detect wafer separation damages but also hold the potential to enable an efficient detection of all kinds of defective LED chips. On a photoluminescence image, every pixel corresponds to an LED chip’s brightness after photoexcitation, revealing performance information. But due to unevenly distributed brightness values and varying defect patterns, photoluminescence images are not yet employed for a comprehensive defect detection. In this work, we show that fully convolutional networks can be used for chip-wise defect detection, trained on a small data-set of photoluminescence images. Pixel-wise labels allow us to classify each and every chip as defective or not. Being measurement-based, labels are easy to procure and our experiments show that existing discrepancies between training images and labels do not hinder network training. Using weighted loss calculation, we were able to equalize our highly unbalanced class categories. Due to the consistent use of skip connections and residual shortcuts, our network is able to predict a variety of structures, from extensive defect clusters up to single defective LED chips.

Soft X-ray diffraction patterns measured by a LiF detector with sub-micrometre resolution and an ultimate dynamic range.

The unique diagnostic possibilities of X-ray diffraction, small X-ray scattering and phase-contrast imaging techniques applied with high-intensity coherent X-ray synchrotron and X-ray free-electron laser radiation can only be fully realized if a sufficient dynamic range and/or spatial resolution of the detector is available. In this work, it is demonstrated that the use of lithium fluoride (LiF) as a photoluminescence (PL) imaging detector allows measuring of an X-ray diffraction image with a dynamic range of ∼107 within the sub-micrometre spatial resolution. At the PETRA III facility, the diffraction pattern created behind a circular aperture with a diameter of 5 µm irradiated by a beam with a photon energy of 500 eV was recorded on a LiF crystal. In the diffraction pattern, the accumulated dose was varied from 1.7 × 105 J cm-3 in the central maximum to 2 × 10-2 J cm-3 in the 16th maximum of diffraction fringes. The period of the last fringe was measured with 0.8 µm width. The PL response of the LiF crystal being used as a detector on the irradiation dose of 500 eV photons was evaluated. For the particular model of laser-scanning confocal microscope Carl Zeiss LSM700, used for the readout of the PL signal, the calibration dependencies on the intensity of photopumping (excitation) radiation (λ = 488 nm) and the gain have been obtained.