Visible Spectral Region Research Articles

Femtosecond-laser-induced suprawavelength two-dimensional ZnO microstructures for multi-wavelength photodetector devices.

Herein, we report on two-dimensional (2D) suprawavelength crystalline ZnO microstructures induced by a single ultraviolet (UV) femtosecond laser beam (400 nm, 35 fs, 666 Hz) with significant absorption enhancement. The achieved absorption values of 90-99% and 75-80% in the UV and visible spectral regions, respectively, were approximately 1.16 and 12 times higher than those of the blank ZnO crystal. Furthermore, large-area 2D ZnO microstructures were fabricated to be used as photodetectors (PDs). The experimental results demonstrated that, compared with the blank ZnO, these 2D ZnO microstructures effectively enhanced the PD performance by nearly four times at 375 nm. More importantly, the ZnO microstructure exhibited great response value, ∼7.12 A/W at 532 nm as well as acceptable response at 660 and 808 nm, whereas the blank ZnO crystal showed almost no response. Raman analyses demonstrated that no change occurred after the femtosecond laser induced the microstructure on ZnO. Thus, the enhancement in photoelectric performance can be attributed to the strong absorption of the ZnO microstructure.

Waste Material Classification Based on a Wavelength-Sensitive Ge-on-Si Photodetector.

Waste material classification is critical for efficient recycling and waste management. This study proposes a novel, low-cost material classification system based on a single, voltage-tunable Ge-on-Si photodetector operating across the visible and short-wave infrared (SWIR) spectral regions. Thanks to its tunability, the sensor is able to extract spectral information, and the system effectively distinguishes between seven different materials, including plastics, aluminum, glass, and paper. The system operates with a broadband illuminator, and material identification is obtained through the processing of the photocurrent signal at different bias voltages with classification algorithms. Here, we demonstrate the basic system functionality and near real-time classification of different waste materials.

Sub-picosecond biphasic ultrafast all-optical switching in ultraviolet band

Abstract Ultrafast all-optical control has been a subject of wide-spread attention as a method of manipulating optical fields using light excitation on extremely short time scales. As a fundamental form of ultrafast all-optical control, all-optical switching has achieved sub-picosecond switch speeds in the visible, infrared, and terahertz spectral regions. However, due to the lack of suitable materials, ultrafast all-optical control in the ultraviolet range remains in its early stages. We demonstrate sub-picosecond all-optical switching in the ultraviolet wavelength by designing a Si3N4-ITO Fabry–Pérot resonance aligns with the edge of the interband transition region of ITO. The response time of 500 fs achieved at a pump fluence as low as 0.17 mJ/cm2. Notably, unlike conventional binary switches (0, 1), this biphasic all-optical switch enables the modulation of optical intensity with positive, zero, and negative ΔR/R (0, 1, −1) at the same wavelength, all achieved with a switching speed of 680 fs at a pump fluence of 0.45 mJ/cm2. This work establishing a new pathway for all-optical control in the ultraviolet spectrum, the biphasic switch provides an extra degree of freedom for all-optical modulation.

Chemically functionalized diamanes - A new class of hybrid 2D materials: DFT insight into crystal, mechanical, and electronic properties

This work describes crystal and electronic structures of a new class of 2D hybrid organic-inorganic compounds based on AB-stacked diamane. Seven members thereof are considered: methyl-, pyrrolyl-, 1,2,4-triazolyl-, phenyl-, pyridinyl-, and pyrimidinyl-substituted (two isomers) diamane. DFT calculations show that an electronic structure of diamane can be modulated by organic functional groups. The chemically functionalized diamanes are semiconductors with HSE06 electronic bandgaps falling in the range [2.09–4.91] eV. Other means of diamane electronic structure tuning include variation of coverage of a diamane surface by substituents, mixing of substituents and changing their mutual orientation. Based on the obtained results we conclude that the functionalized diamanes may serve as photovoltaic materials operable in Vis and near UV spectral regions. Owing to a similarity of the aromatics-substituted diamanes to low-dimensional hybrid metal halide perovskites with aromatic organic cations the former could be photoluminescent. An enhanced resistance of the investigated materials to water is expected.

Dressing AgNWs with MXenes Nanosheets: Transparent Printed Electrodes Combining High-Conductivity and Tunable Work Function for High-Performance Opto-Electronics.

High-work function transparent electrodes (HWFTEs) are key for establishing Schottky and Ohmic contacts with n-type and p-type semiconductors, respectively. However, the development of printable materials that combine high transmittance, low sheet resistance, and tunable work function remains an outstanding challenge. This work reports a high-performance HWFTE composed of Ag nanowires enveloped conformally by Ti3C2Tx nanosheets (TA), forming a shell-core network structure. The printed TA HWFTEs display an ultrahigh transmittance (>94%) from the deep-ultraviolet (DUV) to the entire visible spectral region, a low sheet resistance (<15 Ωsq-1), and a tunable work function ranging from 4.7 to 6.0eV. The introduction of additional oxygen terminations on the Ti3C2Tx surface generates positive dipoles, which not only increases the work function of the TA HWFTEs but also elevates the TA/Ga2O3 Schottky barrier, resulting in a high self-powered responsivity of 18mAW-1 in Ga2O3 diode DUV photodetectors, as demonstrated via experimental characterizations and theoretical calculations. Furthermore, the TA HWFTEs-based organic light-emitting transistors exhibit exceptional emission brightness of 5020cd m-2, being four-fold greater than that in Au electrodes-based devices. The innovative nano-structure design, work function tuning, and the revealed mechanisms of electrode-semiconductor contact physics constitute a substantial advancement in high-performance optoelectronic technology.

Nanosized Eu3+-Doped NaY9Si6O26 Oxyapatite Phosphor: A Comprehensive Insight into Its Hydrothermal Synthesis and Structural, Morphological, Electronic, and Optical Properties.

Detailed analysis covered the optical and structural properties of Eu3+-doped NaY9Si6O26 oxyapatite phosphors, which were obtained via hydrothermal synthesis. X-ray diffraction patterns of NaY9Si6O26:xEu3+ (x = 0, 1, 5, 7, 10 mol% Eu3+) samples proved a single-phase hexagonal structure (P63/m (176) space group). Differential thermal analysis showed an exothermic peak at 995 °C attributed to the amorphous to crystalline transformation of NaY9Si6O26. Electron microscopy showed agglomerates composed of round-shaped nanoparticles ~53 nm in size. Room temperature photoluminescent emission spectra consisted of emission bands in the visible spectral region corresponding to 5D0 → 7FJ (J = 0, 1, 2, 3, 4) f-f transitions of Eu3+. Lifetime measurements showed that the Eu3+ concentration had no substantial effect on the rather long 5D0-level lifetime. The Eu3+ energy levels in the structure were determined using room-temperature excitation/emission spectra. Using the 7F1 manifold, the Nv-crystal field strength parameter was calculated to be 1442.65 cm-1. Structural, electronic, and optical properties were calculated to determine the band gap value, density of states, and index of refraction. The calculated direct band gap value was 4.665 eV (local density approximation) and 3.765 eV (general gradient approximation). Finally, the complete Judd-Ofelt analysis performed on all samples confirmed the experimental findings.

Electron Spin Dynamics of the Intersystem Crossing in Aminoanthraquinone Derivatives: The Spectral Telltale of Short Triplet Excited States.

We studied the excited state dynamics of two bis-amino substituted anthraquinone (AQ) derivatives, with absorption in the visible spectral region, which results from the attachment of a electron-donating group to the electron-deficient AQ chromophore. Femtosecond transient absorption spectra show that intersystem crossing (ISC) takes place in 190-320 ps, and nanosecond transient absorption spectra demonstrated an unusually short triplet state lifetime (2.06-5.43 μs) for the two AQ derivatives. Pulsed laser-excited time-resolved electron paramagnetic resonance (TREPR) spectra show an inversion of the electron spin polarization (ESP) phase pattern of the triplet state at a longer delay time after laser flash. Spectral simulations show faster decay of the Ty sublevel than the other two sublevels (τx = 15.0 μs, τy = 1.50 μs, τz = 15.0 μs); theoretical computation predicts initial overpopulation of the Ty sublevel, and rationalizes the short T1 state lifetime and the ESP inversion. Theoretical computations taking into account the electron-vibrational coupling, i.e., the Herzberg-Teller effect, successfully rationalize the TREPR experimental observations.

Critical current density of high-temperature superconducting ceramics BSCCO Bi-2223

In the paper the results of the study on the synthesis of high-temperature superconducting ceramics of nomi- nal composition Bi1.6Pb0.4Sr2Ca2Cu3Oy by various methods were presented based on amorphous phases using glass-ceramic technology and solid-phase method. For comparison, amorphous phases were obtained in two ways. In the first case, a heating furnace of a special design was developed to obtain an amorphous phase, which provides melting without using a crucible. The heating of the initial samples for melting is carried out due to the combined effect of the convection heat flux and the radiation of heating elements, which consists of the IR region of the spectrum at a melting temperature in the spectral range of 1300–1350 nm. In the se- cond case, melting is carried out under the influence of broadband optical radiation, including UV, visible and IR spectral regions. The production of glassy precursors is carried out by draining the melt onto a quenching device in the form of a propeller made of stainless steel. Studies of the formation rate of the superconducting high-temperature phase Bi-2223 were carried out in the same temperature conditions at 848–850 °C with in- termediate grinding every 24 hours and the study of the phase composition by X-ray diffraction method. Studies showed that the glass phase-based method ensures the completeness of the formation of the high- temperature phase Bi-2223 and the rate of its formation is significantly higher than by the solid-phase method (2.5–3 times). Studies of the critical density of the transport current have shown that the current value is 7.05×103 mA/cm2, (measured by the criterion of 1 µV/cm), which is significantly higher compared to other methods.

Transparent rare earth‐doped gallium oxide ceramics with oriented microstructure

AbstractGallium oxide (Ga2O3) has attracted much attention due to its promising applications in optical and electronic devices, while it is difficult to fabricate high‐quality Ga2O3 transparent ceramics because of the non‐cubic crystal structure. In this work, fully densified undoped and rare earth (RE = Tb, Dy. Er)‐doped Ga2O3 transparent ceramics were successfully fabricated by using spark plasma sintering (SPS) and co‐precipitated ceramic powders. Both the powders and ceramics showed pure monoclinic β‐ Ga2O3 crystal structure and unique orientation. After sintering by SPS for 30 min, all the ceramics reached a relative density higher than 99.21%. The total transmittance of RE‐doped Ga2O3 transparent ceramics ranges from 60% to 69% originating from the oriented and dense microstructures. The photoluminescence spectra and fluorescence lifetime of RE‐doped Ga2O3 transparent ceramics confirm characteristics of energy transfers corresponding to Tb3+, Dy3+, or Er3+ ions in the visible and NIR spectral region. This study demonstrates that oriented RE‐doped Ga2O3 transparent ceramics have great potential to be used in various optical applications.

BAs/BlueP van der Waals heterostructures for photovoltaic and thermoelectric applications

The advancement of novel energy materials, encompassing photovoltaic and thermoelectric materials, assumes paramount significance in ameliorating the energy crisis and proactively combating climate change. The BAs/BlueP van der Waals heterostructure (vdWH), characterized by its outstanding optical absorption properties, high power conversion efficiency (PCE), and excellent thermoelectric performance, offers novel insights into the advancement of materials for photonic and thermoelectric applications. We have engineered a vdWH by combining BAs and BlueP, and conducted a comprehensive investigation of its electronic, optical, and thermoelectric properties. The BAs/BlueP vdWH demonstrates excellent thermodynamic and kinetic stability with type I band alignment, facilitating rapid interlayer electron-hole recombination. The remarkable optical absorption capability within the visible and ultraviolet (UV) spectral regions, coupled with an outstanding power conversion efficiency reaching up to 22.35 % under strain, firmly establishes the potential for utilization in photovoltaic conversion applications. At 1000 K, the significant ZT value (1.25) and high thermoelectric conversion efficiency (19.45 %) provide the theoretical foundation for its application in the field of thermoelectrics.

A XRD Study of the CuAl Layered Double Hydroxide Synthesis Evolution

It is a challenge to determine the active part of a solid phase in chemical process when the purity of the aforesaid is not sufficient and could jeopardize the solid real applications. CuAl LDH phase has been obtained with low percentage of impurities and the intention to use it as photoreduction or photoxidation catalyst and /or templating agent in the design of nanohybrid composites photocatalysts, for CO2 storage that could facilitate its later abatement and/or highly efficient semiconductor material. A set of synthesis were implemented with a mixture of Cu(NO3)22.5H2O and Al(NO3)3.9H2O with Na2CO3 and NaOH using coprecipitation at variable pH. Keeping constant a low CO32-/Cu2+ + Al3+ fraction in all sets, constant basic pH and ageing time (96h) with slight variations in T, resulted in mixed phases of malachite, CuAl LDH and traces of Cu(OH)2. At basic pH and T with different ageing time, similar XRD patterns were measured with noticeable differences, though. When the carbonate ratio, ageing time, and pH were constant (7.50, 96 h, 9.24), modest changes in T generated key dissimilitude in the diffractograms. The resulting band gap energy of this LDH coincided with the visible spectral region energy. A more precise tuning of variables has led to a high degree of optimization of the CuAl LDH and further contributes to comprehend how varied synthesis conditions influence this metastable hydrotalcite Obtention.

Structural and optoelectronic studies of BiCuOS semiconductor: A potential photoconverter

As a p-type semiconductor, Bismuth copper oxysulfide (BiCuOS) with a narrow bandgap has exceptional absorption characteristics in the visible and near-infrared spectral regions, which have good application prospects for optoelectronic devices. A simple hydrothermal technique is successfully employed for the complicated material synthesis. The desired phase formation of the material has been investigated by varying the reaction time in the procedure, and it is observed to be crucial in maximizing the yield of this material. The scanning electron microscope (SEM) and transmission electron microscope (TEM) are utilized to analyze the morphological and lattice arrangements of the prepared sample. The photodetection performance of the material is assessed through the fabrication of a self-powered p-n heterojunction photodetector with grown n-type ZnO. At self-powered conditions, the device showed a better spectral responsivity of 118 μA/W,detectivity of around 8.27 × 107 Jones, and linear dynamic range (LDR) of 5.7 Hz. The proposed interface of oxychalcogenide semiconductor is anticipated to broaden the research on its improvement and usage in various optoelectronic applications.

Optically enhanced organic phototransistors for adaptive image processing under complex light conditions

Effectively handling massive information in complex lighting conditions is crucial for security-focused machine vision, as it relies on precise image feature detection and encryption/decryption to ensure integrity and confidentiality. Traditional hardware, primarily based on complementary metal-oxide-semiconductor (CMOS) technology, struggles with the complexity of processing tasks around the clock. To address this challenge, a ternary organic heterostructure visuomorphic phototransistor was tailored for adaptive critical image processing. The light coupling induced by the porous heterostructural layer enhances the light absorption efficiency by 2.5-fold. Our phototransistor exhibits bidirectional photoresponse across the visible and near-infrared (NIR) spectral regions, enabling adaptive edge detection in varying lighting conditions with precision above 85 %. The phototransistor array facilitates image encryption/decryption with a superior accuracy of 12 %/90 % compared to existing counterparts. This ternary organic hetero-integration combines multiple response modes, enabling compact and efficient critical feature processing.

(Dielectric Science & Technology Thomas Callinan Award) Rare-Earth Luminescence in Silicon-Based Thin Film Structures

For Si-based materials to be used in solid-state lighting and silicon photonics schemes it is necessary to have precise control of the optical emission from these materials. This can be accomplished using rare earth dopants such as Ce, Tb, and Eu to obtain blue, green, and red emissions, respectively. In this talk, we first will provide a review of our work in this field and then focus on Eu-doped films, which are particularly attractive for silicon photonic applications due to their intense emission in the visible spectral region [1]. We will also discuss the benefits of introducing a novel hybrid radio frequency (RF) magnetron sputtering source in the electron cyclotron resonance (ECR) plasma enhanced chemical vapour deposition (PECVD) reactor chamber [2], using the example of Tb-doped SiON films [3]. This approach contrasts with traditional doping methods which use metal-organic precursors or ion implantation to introduce rare-earth dopant species into the host matrix.[1] F. Azmi et al., “Tunable Emission from Eu:SiOxNy Thin Films Prepared by Integrated Magnetron Sputtering and Plasma Enhanced Chemical Vapor Deposition”, J. Vac. Sci. Technol. A 40, 043402 (2022); DOI: 10.1116/6.0001761[2] J.W. Miller et al., “Integrated ECR-PECVD and Magnetron Sputtering System for Rare-Earth-Doped Si-Based Materials”, Surface and Coatings Technology 336, 99 (2018); DOI: 10.1016/j.surfcoat.2017.08.051[3] Z. Khatami et al., "A comprehensive calibration of integrated magnetron sputtering and plasma enhanced chemical vapor deposition for rare-earth doped thin films", J. Mater. Res. (2023); DOI: 10.1557/s43578-023-01207-2

The Diverse Electrochemistry and Photophysics of Pyrrolopyrroles

Pyrrole is among the most popular molecular scaffolds for biology. Tetrapyrroles, such as porphyrins, corrins and their derivatives, are the quintessential redox centers and chromophores exhibiting a wide range of electrochemical and optical characteristics. Similarly, pyrrolopyrroles, built on condensed five-member rings with nitrogens as heteroatoms, offer scaffolds for organic chromophores with diversity of redox and photophysical properties. For example, pyrrolo[3,2-b]pyrroles are stable electron-rich UV absorbers with quadrupole symmetry (Acc. Chem. Res. 2017, 50, 2334-2345). They can act as immensely potent electron donors and attaching electron-accepting moieties to them leads to the emergence of a myriad of optical phenomena, such as excited-state symmetry breaking (Commun. Chem. 2020, 3, 190) and generating white fluorescence by tuning donor-acceptor electronic coupling (Chem. Sci. 2023). Attaching carbonyls to the pyrrolopyrrole rings drastically changes their electronic properties, making them pronouncedly electron deficient and shifting their absorption to the visible spectral region. For example, 2,5-dihydropyrrolo[3,4-c]pyrrole-1,4-diones, or diketopyrrolopyrroles (DPPs) for short, are excellent electron acceptors and photooxidants (Adv. Opt. Matter. 2015, 3, 2018-320). Their reduction potentials are susceptible to localized electric fields, which has allowed demonstrating dipole-induced rectification of photoinduced hole transfer (Angew. Chem. Int. Ed. 2018, 57, 12365-12369). This field susceptibility extends to the optical properties of DPPs, providing an extra dimension in their utility for photonics and optoelectronics. DPPs, and pyrrolopyrroles in general, are built on small bicyclic scaffolds, i.e., considerably smaller than those of other multi-pyrrole chromophores. The small size enhances the susceptibility of their redox properties to solvation and makes them attractive photoprobes. Therefore, this class of compounds have become indispensable agents for electrochemical and photonic science and engineering.

(Invited) Synthesis of Ultra-Bright Colloidal Silicon Quantum Dots (PLQY~80%) and Highly Efficient LEDs (EQE>10%)

Silicon is the second most abundant element in the Earth’s crust and could be considered an environmentally benign material. Silicon has been widely used in electronic devices and solar cells, and it has dominated the semiconductor research and development. However, the photoluminescence (PL) of the bulk material shows an invisible NIR wavelength (λ ~ 1100 nm). In addition, the PL quantum yield (PLQY) of bulk crystal Si is ~0.01% owing to the indirect transition nature. In contrast, silicon quantum dots show PL in the entire visible spectral region [1]. Furthermore, colloidal silicon quantum dots demonstrate PLQYs of 60% [2], and thereby they give highly impact as environmentally benign and heavy-metal-free quantum dots (i.e., In, Cd, and Pb free) for displays, lighting, and biomedical imaging via solution processing. Indeed, silicon quantum dot LEDs have recently been produced from a natural substance, by upcycling discarded rice husks [3].Herein, red PL with a PLQY of 60–80% and LEDs with an external quantum efficiency of >10% were obtained at 1/3600th of the cost of existing methods. This was achieved by using trichlorosilane and an organic solvent to prepare a hydrogen silsesquioxane (HSQ) polymer, and by optimizing the LED optoelectric properties. Based on many silicon quantum dots synthesized in our study, each of them enabled us to quantitative the relationships HSQ polymer structure, PLQY, and LED efficiency, exhibiting the critical parameters that governed their performances. Moreover, the simple and cost-effective methods proposed here could prove invaluable for the synthesis and characterization of silicon quantum dots in the near future.

Revisiting the statistical equilibrium of H- in stellar atmospheres

The negative hydrogen ion is, almost without exception, treated in local thermodynamic equilibrium (LTE) in the modelling of F, G, and K stars, where it is the dominant opacity source in the visual spectral region. This assumption rests in practice on a study from the 1960s. Since that work, knowledge of relevant atomic processes and theoretical calculations of stellar atmospheres and their spectra have advanced significantly, but this question has not been reexamined. We present calculations based on a slightly modified analytical model that includes H and together with modern atomic data and a grid of 1D LTE theoretical stellar atmosphere models with stellar parameters ranging from T$_ eff = 4000$ to 7000 K, $ g = 1$ to 5 cm/s$^2$, and Fe/H $=-3$ to 0. We find direct non-LTE effects on populations in spectrum-forming regions, continua, and spectral lines of about 1--2&lt;!PCT!&gt; in stars with higher T$_ eff $ and/or lower $ g$. Effects in models for solar parameters are smaller by a factor of 10, about 0.1--0.2&lt;!PCT!&gt;, and are practically absent in models with lower T$_ eff $ and/or higher $ g$. These departures from LTE found in our calculations originate from the radiative recombination of electrons with hydrogen to form exceeding photodetachment, that is, overrecombination. Modern atomic data are not a source of significant differences compared to the previous work, although detailed data for processes on resolved with vibrational and rotational states provide a more complete and complex picture of the role of in the equilibrium of In the context of modern studies of stellar spectra at the percent level, our results suggest that this question requires further attention, including a more extensive reaction network, and indirect effects due to non-LTE electron populations.

Unravelling Structural, Optical, and Band Alignment Properties of Mixed Pb-Sn Metal-Halide Quasi-2D Ruddlesden-Popper Perovskites.

Lead-tin (Pb-Sn) mixed-halide perovskites show potential for single-junction and tandem solar cells due to their adjustable band gaps, flexible composition, and superior environmental stability compared to three-dimensional (3D) perovskites. However, they have lower power conversion efficiencies. Understanding band alignment and charge carrier dynamics is essential for enhancing photovoltaic performance. In this view, herein we have prepared thin films of mixed Pb-Sn-based two dimensional (2D) Ruddlesden-Popper (RP) perovskites BA2FA(Pb1-xSnx)2I7 using a solution-based method. XRD study revealed the formation of orthorhombic phases for pristine (BA2FAPb2I7) and mixed Pb-Sn perovskite thin films. UV-vis analysis showed that different n = 2 and n = 3 phases are present in the pristine sample. In contrast, Pb-Sn-doped samples showed no signature of other phases with a prominent red-shift in the visible spectral region. Cyclic voltammetry showed peaks for electron transfers at the band edges. Additionally, electrochemical and optical band gap matching was observed, along with decreased peak intensity due to less reactant and altered electrolyte-perovskite interface stability. Density functional theory (DFT) calculations revealed that the reduced band gap is due to the alteration of electrostatic interactions and charge distribution within the lattice upon Sn substitution. Low-temperature PL analysis provided insights into charge carrier dynamics with Sn substitution and suggested the suppression of higher n phases and self-trapped excitons/carriers in mixed Pb-Sn quasi-2D RP perovskite thin films. This study sheds light on the electron transfer phenomena between TiO2 and SnO2 layers by estimating band offsets from valence band maximum (VBM) and conduction band minimum (CBM), which is crucial for future applications in fabricating stable and efficient 2D-Pb-Sn mixed perovskites for optoelectronic applications.

Multidimensional fluorescence spectroscopy of wine using synchronous excitation/emission matrices and time-resolved fluorescence interferometric detection

Wines are complex mixtures of chemical compounds with broad and overlapping absorption and emission spectral features in the UV and visible spectral regions, making them challenging to study with conventional optical spectroscopic techniques. Multidimensional fluorescence spectroscopies correlate fluorescence spectra with other degrees of freedom, and have proven useful for studying complex molecular systems, offering a pathway for the analysis of wines utilising their inherent fluorescence. Here we employ steady-state excitation-emission matrix (EEM) and time-resolved fluorescence spectral measurements to investigate representative commercial white and red wine samples and a fluorescent ‘model’ wine base. Combining these multidimensional measurement methods provides information on the emission characteristics of the components that wines contain. This investigation illustrates the potential for multidimensional fluorescence techniques as diagnostic tools for the wine industry.

Circularly Polarized Luminescence from Pure and Eu-Doped Trigonal TbPO4·nH2O Nanocrystals.

In this contribution, we describe the preparation, by means of a precipitation reaction from aqueous solution at 40 °C, and the structural characterization of nanocrystalline powders of trigonal Tb1-xEuxPO4·nH2O (with x = 0, 0.005, 0.01, 0.05, and 0.1; n tentatively assigned as 0.67) which crystallize in the two possible P3121 or P3221 enantiomorphic space groups. While the volume of the crystal lattice is not significantly affected by the Tb3+/Eu3+ substitution, the average crystallite size seems to depend on the Eu3+ dopant concentration and ranges from 13 to 30 nm. The desired handedness of the crystals has been induced by using, during the synthesis, one of the two possible enantiomers of tartaric acid (l or d). The analysis of the luminescence excitation and emission spectra, together with the decay kinetics of the 5D4 Tb3+ excited state, suggests the presence of a very efficient Tb3+ → Eu3+ energy transfer process in the Eu3+-doped orthophosphates. Upon excitation of Tb3+ ions at 368 nm, the enantiomorphic powders grown with l- or d-tartaric acid (i.e., l-TbPO4·0.67H2O/d-TbPO4·0.67H2O, l-Tb0.995Eu0.005PO4·0.67H2O/d-Tb0.995Eu0.005PO4·0.67H2O, and l-Tb0.9Eu0.1PO4·0.67H2O/d-Tb0.9Eu0.1PO4·0.67H2O) exhibited mirror circularly polarized luminescence signals in the visible spectral region (in the green and/or in the red).