Size-dependent Shift Research Articles

Coexistence of the Band Filling Effect and Trap-State Filling in the Size-Dependent Photoluminescence Blue Shift of MAPbBr3 Nanoparticles.

The size-dependent photoluminescence (PL) blue shift in organometal halide perovskite nanoparticles has traditionally been attributed to quantum confinement effects (QCEs), irrespective of nanoparticle size. However, this interpretation lacks rigor for nanoparticles with diameters exceeding the exciton Bohr radius (rB). To address this, we investigated the PL of MAPbBr3 nanoparticles (MNPs) with diameters ranging from ~2 to 20 nm. By applying the Brus equation and Burstein-Moss theory to fit the PL and absorption blue shifts, we found that for MNPs larger than rB, the blue shift is not predominantly governed by QCEs but aligns closely with the band filling effect. This was further corroborated by a pronounced excitation-density-dependent PL blue shift (Burstein-Moss shift) at high photoexcitation densities. Additionally, trap-state filling was also found to be not a negligible origin of the PL blue shift, especially for the smaller MNPs. The time-resolved PL spectra (TRPL) and excitation-density-dependent TRPL are collected to support the coexistence of both filling effects by the high initial carrier density (~1017-1018 cm-3) and the recombination dynamics of localized excitons and free carriers in the excited state. These findings underscore the combined role of the band filling and trap-state filling effects in the size-dependent PL blue shift for solution-prepared MNPs with diameters larger than rB, offering new insights into the intrinsic PL blue shift in organometal halide perovskite nanoparticles.

Inverted V-shaped size-dependent emission wavelength shift in InGaN micro-LEDs with size down to 1 μm

The size-dependent emission wavelength shift of micro-scale light emitting diodes (micro-LEDs) has been frequently reported in recent publications, but its underlying physical mechanism has not yet been thoroughly elucidated. Here, we fabricate and characterize the red, green, and blue InGaN micro-LED mesas with different diameters down to 1 μm. As the size decreases, all the samples of different colors show an inverted V-shaped photoluminescence wavelength variation trend, first a red shift and then a blue shift, and the shifting range is larger for samples with longer wavelengths. Micro-Raman spectrum confirms that the stress was significantly released after scaling down the size from epitaxial wafer to 1 μm. The theoretical simulations show that the red and blue shifts are, respectively, attributed to the bandgap narrowing and the weakening of the quantum-confined Stark effect caused by strain relaxation, which dominate successively.

Phase Transition of Cubic Ice to Hexagonal Ice during Growth and Decomposition.

Ice, one of the most enigmatic materials on Earth, exhibits diverse polymorphism, with research mainly focusing on the most commonly observed phases: hexagonal ice (Ih), cubic ice (Ic), and stacking-disordered ice (Isd). While their formation or structural changes are crucial for advancements in cloud science, climate modeling, and cryogenic technology, the molecular mechanisms driving these phenomena remain unexplored. Herein, utilizing cryogenic transmission electron microscopy, we investigate the formation of ice at two different temperatures, demonstrating a size-dependent phase shift from Ic to Isd. Furthermore, a relatively metastable cubic phase in Isd transitions to a hexagonal phase under electron beam radiation. This transition, facilitated by crystal defects, contrasts with perfect crystalline Ic, which maintains its original phase, emphasizing the importance of defects in polymorphic phase transitions. Our findings provide novel insights on phase control during the ice growth processes and polymorphic phase transitions from the cubic-to-hexagonal phases.

Relationship between stable cesium concentration and body size of Japanese flounder Paralichthys olivaceus and the effect of a size-dependent shift in diet.

To understand the relationship between the radioactive cesium (Cs) concentration in muscle of Japanese flounder Paralichthys olivaceus and the species' biological characteristics (size, sex, and age) under conditions of ecological equilibrium (i.e., distributed among ecosystem components over sufficient time, and with nearly constant ratios of Cs concentration in organisms to the concentration in water) as existed before the accident at the Fukushima Dai-ichi Nuclear Power Station (FDNPS), Japan, in 2011, we examined stable Cs, as it is thought to exist in equilibrium in the environment and behave similarly to radioactive Cs in aquatic animals. The concentration of stable Cs in 241 P. olivaceus (range 216-782 mm total length [TL]) collected in Sendai Bay, approximately 90 km north of the FDNPS, in June-July 2015 was expressed as an exponential function with size as an independent variable; the results show the concentration of stable Cs doubled with an increase in TL of 442 mm. Next, to evaluate the cause of the size-dependent change in stable Cs concentration, we examined 909 individuals (200-770 mm TL) collected in September 2013-July 2015 to determine their feeding habit based on size. Analysis of the frequency of occurrence of prey organisms in stomach contents showed that sand lance Ammodytes japonicus (55-180 mm standard length [SL]) was the most consistently consumed across size classes. Analysis on a wet-mass basis showed that A. japonicus and anchovy Engraulis japonicus (65-130 mm SL) were the main food of P. olivaceus sized 200-599 mm TL, whereas chub mackerel Scomber japonicus (120-230 mm SL) and two species of flatfishes (180-205 mm SL) were abundant in the diet of P. olivaceus sized ≥600 mm TL. All these prey items were presumed to have similar concentrations of stable Cs. Based on the above, the effect of diet on the relationship between stable Cs in muscle and fish size was considered negligible. That the diet of P. olivaceus largely did not change with size was also confirmed by C and N stable isotope ratios in P. olivaceus and their prey species. Therefore, the Cs-size relationship is probably determined by changes in the balance between the rate of Cs intake from food and seawater and the excretion rate during growth, both of which change as functions of body mass. Values of stable Cs concentrations among environmental components and animals appear to be a valid indicator for understanding the radioactive Cs distribution in the marine environment and aquatic animals under the equilibrium state, as existed before the 2011 nuclear accident.

Prediction of the Size-Dependent Raman Shift of Semiconductor Nanomaterials via Deep Learning

Raman spectroscopy can characterize size-related properties of semiconductor nanomaterials according to the change of Raman shift. When limited to physical mechanisms, it is often difficult to predict the size-dependent Raman shift of semiconductor nanomaterials. To predict the size-dependent Raman shift more accurately and efficiently, a simple and effective method was created, demonstrated, and achieved via the deep learning model. The deep learning model is implemented by multi-layer perceptron. For size-dependent Raman shifts of three common semiconductor nanomaterials (InP, Si, CeO2), the prediction error was 1.47%, 1.18%, and 0.58%, respectively. The research has practical value in material characterization and related engineering applications, where physical mechanisms are not the focus and building predictive models quickly is key.

Size-dependent radiative recombination characteristics of isolated CuInS2 nanocrystals

Ternary chalcopyrite semiconductor nanocrystals of the I–III–VI2 type are potential nontoxic alternatives to Cd- and Pb-based chalcogenide nanocrystals, which can be adopted for light emission and photovoltaic applications. Most I–III–VI2 nanocrystals exhibit luminescence originated from defect-related recombination, which is characterized by a broad spectrum with a large Stokes shift regardless of the size-dependent spectral shift due to the quantum size effect. However, the origin of the luminescence in I–III–VI2 nanocrystals is still under debate, and deeper investigations of the carrier recombination processes are necessary to gain further understanding of the luminescence mechanisms. For this purpose, we investigated the temperature dependence of the luminescence properties of CuInS2 nanocrystals down to cryogenic temperatures to suppress the nonradiative recombination. The intrinsic luminescence properties of the isolated CuInS2 nanocrystals were successfully evaluated by eliminating the influence of the interactions among the nanocrystals, which is different from previous studies on nanocrystal aggregates. Both the thermal quenching behavior and the temperature dependence of the carrier recombination rate could be satisfactorily described using a simple model that assumes a thermally activated nonradiative recombination. The radiative recombination rates of the CuInS2 nanocrystals were found to be 106–107 s−1, and a characteristic cubic dependence of the radiative recombination rate on the nanocrystal diameter was found.

Explanation of the Opposing Shifts in the Absorption Edge and the Optical Resonance in CuFeS2 Nanoparticles

Size-dependent change of the electronic band structure is one of the key features of nanoparticles in the quantum confinement region. CuFeS2 nanoparticles have a strong absorption feature in the visible region that has, controversially, been described as neither an excitonic transition nor a free carrier plasmon oscillation. Instead, the absorption feature in CuFeS2 nanoparticles has been attributed to quasi-static optical resonances from inter-band transitions between the valence band (VB), intermediate band (IB), and conduction band (CB). As such, we hypothesized that the feature should be subject to quantum confinement effects through modification of the electronic bands. In this paper, we show experimentally that the optical resonance absorption peak red-shifts and the optical band gap blue-shifts as the particle size decreases. Through density functional theory (DFT) and the tight binding (TB) modeling, we elucidate the size dependence of the band structure, especially focusing on the change in the IB. Using a Lorentzian oscillator optical model to simulate the absorption spectrum with inputs from the DFT-calculated band structure and band shifts from the TB model, we find that the size-dependent shifts of the optical resonance peak position in CuFeS2 are due to a tri-band quantum confinement effect that results in both the VB to IB and IB to CB gap expansion that accompanies a decrease in particle size. We also find that the transitions between the IB and CB play only a minor role in the optical spectrum. Moreover, the linear optical Lorentzian model predicts that the optical resonance peak is tunable across the visible range by partially filling the IB, lowering the CB, or expanding the IB.

Defect Tolerance Mechanism Revealed! Influence of Polaron Occupied Surface Trap States on CsPbBr3 Nanocrystal Photoluminescence: Ab Initio Excited-State Dynamics.

Lead halide perovskite (LHP) nanocrystals (NCs) show exceptional defect tolerance which has been attributed to their unique electronic structure, where defect energy levels are not introduced inside the fundamental bandgap, and the role of polarons in screening charge carriers from defects. Here, we use ab initio atomistic simulations to explore the interplay between various surface chemistries (A = Cs+, R'NH3+; X = Br-, RCOO-) used to passivate a CsPbBr3 NC surface and their impact on the ground-state (GS) and excited-state (ES) photophysical properties. We investigate pristine fully passivated surfaces and A-X vacancy defects that reflect chemical reactions A+ + X- → AX on the surface, which result in ligand desorption. For each surface configuration, calculations are performed in the GS and lowest ES (L-ES) electronic configurations, approximating polaron formation after photoexcitation. For models with A-X surface vacancies, we find that localized electron surface trap (ST) states emerge ∼100-400 meV below the pristine Se band in the L-ES configuration due to polaronic nuclear reorganization. Surprisingly, these trap states contribute relatively bright Sh → ST spectral features. To test if these surface trap states remain bright in a dynamic (thermal) situation we implement excited-state molecular dynamics simulations. It is found that the surface defected model shows an enhanced nonradiative recombination rate which reduces the photoluminescence quantum yield (PLQY) from 95% for the pristine surface to 75%. This is accompanied by an order of magnitude reduction in PL intensity and a red shift of the transition energy. This study provides more evidence of the defect tolerance of LHP NCs along with evidence of surface trap states contributing to efficient photoluminescence. The observation of relatively bright surface trap states could provide insight into photophysical phenomena, such as size-dependent stretched-exponential photoluminescence decay and Stokes shifts.

Improvement of absorption light of laser texturing on silicon surface for optoelectronic application

This work aim to achieving laser nano-textured Si structures by means of an ultra-fast ultra-violet femtosecond (fs) laser texturing technique. The evidences of the impact of the duration of irradiation of the femtosecond laser pulses on Silicon (Si) have been investigated experimentally. A Ti:Sapphire laser at 800 nm (130 fs pulse duration with 1 kHz rate of repetition) has been employed to create nano-textured surfaces in an n-type (111) Si wafer of 0.015 Ω.cm resistivity and 508 ± 5 μm thickness. The average sizes of diameters were estimated to be in the 25−45 nm. From PL measurements of Si nanostructures, size dependent shifts in the direction of the blue spectral region have been emphasized. A highly symmetrical band shape was recognized from the samples' Raman spectra after the irradiation, the phonon frequency (phonon peak shift) shifted below 520 cm−1. The surface nanostructured Si showed lower reflectance values compared with bulk Si (un-irradiated). The observed enhancement of the fabricated Si nanostructures broad spectral response, which is in the range between the visible to the near infrared (NIR) 400−1150 nm, was attributed to increasing light absorption within sub-nanostructures. Thus, the proposed technique could be a promising approach to enhance the performance of Si-based photo-detector.

Formation of size-tunable CdS rhombic dodecahedra

Zinc blende-phased CdS rhombic dodecahedra have been synthesized for the first time in an aqueous solution. The nanocrystals display size-dependent light absorption and emission band shifts and hence band gaps.

Long-term survey of sea turtles (Caretta caretta) reveals correlations between parasite infection, feeding ecology, reproductive success and population dynamics

Long-term monitoring of host-parasite interactions is important for understanding the consequences of infection on host fitness and population dynamics. In an eight-year survey of the loggerhead sea turtle (Caretta caretta) population nesting in Cabo Verde, we determined the spatiotemporal variation of Ozobranchus margoi, a sanguivorous leech best known as a vector for sea turtle fibropapilloma virus. We quantified O. margoi association with turtles’ δ15N and δ13C stable isotopes to identify where infection occurs. We then measured the influence of infection on reproduction and offspring fitness. We found that parasite prevalence has increased from 10% of the population in 2010, to 33% in 2017. Stable isotope analysis of host skin samples suggests transmission occurs within the host’s feeding grounds. Interestingly, we found a significant interaction between individual size and infection on the reproductive success of turtles. Specifically, small, infected females produced fewer offspring of poorer condition, while in contrast, large, infected turtles produced greater clutch sizes and larger offspring. We interpret this interaction as evidence, upon infection, for a size-dependent shift in reproductive strategy from bet hedging to terminal investment, altering population dynamics. This link between infection and reproduction underscores the importance of using long-term monitoring to quantify the impact of disease dynamics over time.

Raman spectroscopy of Bi2Se3-xTex (x = 0–3) topological insulator crystals

We report crystal growth and Raman spectroscopy characterization of pure and mixed bulk topological insulators Bi2Se3-xTex (x = 0–3). The series comprises of both binary (Bi2Se3, Bi2Te3) and ternary tetradymite (Bi2Se1Te2, Bi2Se2Te1, Bi2Se1·5Te1.5) topological insulators. We analyzed in detail the Raman peaks of vibrational modes viz. out of plane A11g, A12g and in-plane Eg2 for both binary and ternary tetradymite topological insulators. Both out of plane A11g and A12g exhibit obvious atomic size dependent peak shift and the effect is much lesser for the former than the later. The situation is rather interesting for in-plane Eg2, which not only show the shift but rather a broader hump like structure. The de-convolution of the same show two clear peaks, which are understood in terms of the presence of separate in plane Bi–Se(I) and Bi–Te(I) modes in mixed tetradymite (Bi2Se2Te1 and Bi2Se1·5Te1.5) topological insulators. Summarily, various Raman modes of well-characterized pure and mixed topological insulator single crystals are reported and discussed in this article.

Universal Size-Dependent Stokes Shifts in Lead Halide Perovskite Nanocrystals.

Size-dependent photoluminescence Stokes shifts (ΔEs) universally exist in CsPbX3 (X = Cl-, Br-, or I-) perovskite nanocrystals (NCs). ΔEs values, which range from ∼15 to 100 meV for NCs with average edge lengths (l) from approximately 13 to 3 nm, are halide-dependent such that ΔEs(CsPbI3) > ΔEs(CsPbBr3) ≳ ΔEs(CsPbCl3). Observed size-dependent Stokes shifts are not artifacts of ensemble size distributions as demonstrated through measurements of single CsPbBr3 NC Stokes shifts (⟨ΔEs⟩ = 42 ± 5 meV), which are in near quantitative agreement with associated ensemble (l = 6.8 ± 0.8 nm) ΔEs values (ΔEs ≈ 50 meV). Transient differential absorption measurements additionally illustrate no significant spectral dynamics on the picosecond time scale that would contribute to ΔEs. This excludes polaron formation as being responsible for ΔEs. Altogether, the results point to an origin for ΔEs, intrinsic to the size-dependent electronic properties of individual perovskite NCs.

Particle Size Effect on Platinum Dissolution: Considerations for Accelerated Stability Testing of Fuel Cell Catalysts

Polymer electrolyte membrane fuel cells (PEMFCs) are highly attractive for use in electric vehicles. In PEMFCs, small particle sizes of the Pt catalyst are required to increase Pt utilization, which lower costs and also increase Pt dispersion, which itself minimizes O2 mass transport losses. Reducing the particle size improves both the utilization and dispersion; however, stability of small particle sizes is an issue. Pt dissolution, as one of the major degradation mechanisms of PEMFC catalyst layers, is predicted to depend on the particle size. The particle size cannot be independently varied from loading in commercial Pt/C materials that have been used in numerous studies employing accelerated stability tests (ASTs). Therefore, in the study presented here, the Pt particle diameter was varied from 2 to 10 nm by depositing mass-selected nanoparticles on a flat glassy carbon substrate using magnetron sputtering. This allows exclusive control over particle density (interparticle distance) and particle size, which becomes difficult even with advanced synthetic techniques for applied Pt/C materials. Additionally, effects of the 3D porous support are eliminated. These model systems were subjected to an aggressive AST in order to cause significant Pt dissolution, which was monitored online using the scanning flow cell coupled to an inductively coupled plasma mass spectrometer. The results uncover a previously overlooked phenomenon: two competing trends in dissolution from (1) particle passivation caused by particle size-dependent shifts on oxophilicity and (2) electrochemically active surface area. Therefore, crucial impacts of the particle size on degradation may be overlooked in a variety of electrochemical studies, which compare catalytic materials. Finally, suggestions are given for improved ASTs for dissolution, which provide insights into the intrinsic stability of Pt nanoparticles toward dissolution.

Perspectives of characterization and bioconjugation of gold nanoparticles and their application in lateral flow immunosensing.

Gold nanoparticles (AuNPs) are an important component in the field of biomedical diagnostics. Because of its unique physicochemical properties, AuNPs have been widely used in biomedical applications such as photothermal cancer therapy, drug delivery, optical imaging, labeling, and biosensing. In this review, we have described synthesis and characterization techniques for AuNPs with recent advancements. Characterization of AuNPs has played an important role in directing its application in various fields and elaborated understanding of its functioning. The characterization techniques used for the analysis of AuNPs utilize its intrinsic properties, such as surface plasmon resonance (SPR) and size-dependent shift in absorption. These properties of AuNPs are furthermore used for the characterization of bioconjugated AuNPs. Surface conjugation of the AuNPs with biomolecules is explored widely for its use in numerous biosensing applications. Biosensor-based diagnostic devices use AuNPs conjugated with a sensing probe for the detection of a specific analyte. AuNPs are also commonly used as a colorimetric sensor in various point-of-care diagnostic techniques. Lateral flow immunosensing (LFIS) technique utilizes AuNPs for the rapid and sensitive detection of various analytes. LFIS is a paper-based detection technique, where the sample containing the analyte flows through the membrane, interacts with immobilized counterparts, and produces results using a detection probe. AuNPs are used as color markers in LFIS, and the presence of an analyte is indicated by the appearance of colored lines on the membrane. The color is a result of the accumulation of AuNP complexes containing the analyte and probe. Effect of characterization parameters of AuNPs on the sensitivity of LFIS, advantages, and disadvantages of using AuNPs for LFIS are discussed concerning the recent reports. Recent applications of AuNPs in LFIS development for the detection of various biomarkers are summarized comprehensively in the table. The review may offer significant insight into the utility of AuNPs for application in the LFIS technique for future development. Graphical abstract Schematic representation of the various applications of gold nanoparticles.

Air quality intervention during the Nanjing youth olympic games altered PM sources, chemical composition, and toxicological responses

Ambient particulate matter (PM) is a leading global environmental health risk. Current air quality regulations are based on airborne mass concentration. However, PM from different sources have distinct chemical compositions and varied toxicity. Connections between emission control measures, air quality, PM composition, and toxicity remain insufficiently elucidated. The current study assessed the composition and toxicity of PM collected in Nanjing, China before, during, and after an air quality intervention for the 2014 Youth Olympic Games. A co-culture model that mimics the alveolar epithelium with the associated macrophages was created using A549 and THP-1 cells. These cells were exposed to size-segregated inhalable PM samples. The composition and toxicity of the PM samples were influenced by several factors including seasonal variation, emission sources, and the air quality intervention. For example, we observed a size-dependent shift in particle mass concentrations during the air quality intervention with an emphasized proportion of smaller particles (PM2.5) present in the air.The roles of industrial and fuel combustion and traffic emissions were magnified during the emission control period. Our analyses revealed that the PM samples demonstrated differential cytotoxic potencies at equal mass concentrations between sampling periods, locations, and time of day, influenced by variations in the predominant emission sources. Coal combustion and industrial emissions were the most important sources affecting the toxicological responses and displayed the least variation in emission contributions between the sampling periods. In conclusion, emission control mitigated cytotoxicity and oxidative stress for particles larger than 0.2 μm, but there was inadequate evidence to determine if it was the key factor reducing the harmful effects of PM0.2.

Role of the surface density of states in understanding size-dependent surface band bending in GaN nanowires

In semiconductor nanostructures, surface states play a very important role in determining the surface potential or contact potential difference (CPD). We measure the CPD value of individual GaN nanowires (NWs) using Kelvin probe force microscopy (KPFM). The corresponding surface band bending (SBB) is calculated from the measured CPD value and is found to increase with a decrease in the NW size. In order to investigate the size dependence of the SBB, the electronic density of states of the surface atoms of the nanowires at different values of the diameter are calculated using the first-principle density functional theory (DFT). The calculated density of states of the nanowires revealed size-dependent occupancy and shift of conduction band edge. The relative position of the conduction band edge corroborates with size-dependent SBB values obtained from KPFM measurements.

Experimental evidence of gradual size-dependent shifts in body size and growth of fish in response to warming.

A challenge facing ecologists trying to predict responses to climate change is the few recent analogous conditions to use for comparison. For example, negative relationships between ectotherm body size and temperature are common both across natural thermal gradients and in small‐scale experiments. However, it is unknown if short‐term body size responses are representative of long‐term responses. Moreover, to understand population responses to warming, we must recognize that individual responses to temperature may vary over ontogeny. To enable predictions of how climate warming may affect natural populations, we therefore ask how body size and growth may shift in response to increased temperature over life history, and whether short‐ and long‐term growth responses differ. We addressed these questions using a unique setup with multidecadal artificial heating of an enclosed coastal bay in the Baltic Sea and an adjacent reference area (both with unexploited populations), using before‐after control‐impact paired time‐series analyses. We assembled individual growth trajectories of ~13,000 unique individuals of Eurasian perch and found that body growth increased substantially after warming, but the extent depended on body size: Only among small‐bodied perch did growth increase with temperature. Moreover, the strength of this response gradually increased over the 24 year warming period. Our study offers a unique example of how warming can affect fish populations over multiple generations, resulting in gradual changes in body growth, varying as organisms develop. Although increased juvenile growth rates are in line with predictions of the temperature–size rule, the fact that a larger body size at age was maintained over life history contrasts to that same rule. Because the artificially heated area is a contemporary system mimicking a warmer sea, our findings can aid predictions of fish responses to further warming, taking into account that growth responses may vary both over an individual's life history and over time.

Controlled Grafting of Colloidal Nanoparticles on Graphene through Tailored Electrostatic Interaction.

Nanoparticle/graphene hybrid composites have been of great interest in various disciplines due to their unique synergistic physicochemical properties. In this study, we report a facile and generalized synthesis method for preparing nanoparticle/exfoliated graphene (EG) composites by tailored electrostatic interactions. EG was synthesized by an electrochemical method, which produced selectively oxidized graphene sheets at the edges and grain boundaries. These EG sheets were further conjugated with polyethyleneimine to provide positive charges at the edges. The primary organic ligands of the colloidal nanoparticles were exchanged with Cl- or MoS42- anions, generating negatively charged colloidal nanoparticles in polar solvents. By simple electrostatic interactions between the EG and nanoparticles in a solution, nanoparticles were controllably assembled at the edges of the EG. Furthermore, the generality of this process was verified for a wide range of nanoparticles, such as semiconductors, metals, and magnets, on the EG. As a model application, designed composites with size-controlled FeCo nanoparticle/EG were utilized as electromagnetic interference countermeasure materials that showed a size-dependent shift of the frequency ranges on the electromagnetic absorption properties. The current generalized process will offer great potential for the large-scale production of well-designed graphene nanocomposites for electronic and energy applications.

Intracluster proton transfer in protonated benzonitrile-(H2O)n≤6 nanoclusters: hydrated hydronium core for n≥ 2.

Protonation and hydration of aromatic hydrocarbon molecules and their derivatives play a key role in many biological and chemical processes. The recent detection of benzonitrile (BN, cyanobenzene, C6H5CN) in the interstellar medium suggests the existence of its protonated form (H+BN) in both the gas phase and in or on ice grains. Herein, we analyze the vibrational signatures of size-selected protonated clusters composed of BN and water (W, H2O), H+(BN-Wn=1-6), in the XH stretch range (X = C, N, O) with the aid of dispersion-corrected density functional theory calculations (B3LYP-D3/aug-cc-pVTZ). The size-dependent frequency shifts provide detailed insight about the site of protonation and the structure of the hydration shell. For n = 1, the proton is attached to the N atom of the CN group in BN, and W acts as a proton acceptor in an NHO ionic hydrogen bond (H-bond) of a H+BN-W type structure with cation-dipole configuration. For n≥ 2, the proton is transferred to the H-bonded hydration network, consistent with thermochemical arguments arising from both the relative proton affinities of BN and Wn and the solvation energies. In these proton-transferred BN-H+Wn structures, the excess proton is more or less localized at a H3O+ hydronium core solvated by neutral W and BN ligands. At least for the considered cluster size (n≤ 6), the BN impurity molecule is located in the first solvation shell of the H3O+ ion, consistent with the larger electric dipole moment and proton affinity of BN as compared to W. However, the energy gap between these structures and surface isomers with BN solvated further away from the charge decreases with cluster size, suggesting that BN is located at the surface in large BN-H+Wn clusters. While for smaller clusters (n≤ 4) the hydration network prefers branched structures at T = 0 K, in larger clusters (n≥ 5) cyclic configurations with four- or five-membered H+Wn rings are most stable because they feature more H-bonds than the branched structures. Comparison with bare H+Wn clusters reveals the substantial effects of the perturbation by the BN impurity on the structure of the hydration network.