Function Of Power Density Research Articles

Intensity Dependent Photoluminescence Imaging for In‐Line Quality Control of Perovskite Thin Film Processing

AbstractLarge area fabrication of high‐quality polycrystalline perovskite thin films remains one of the key challenges for the commercial readiness of perovskite photovoltaic (PV). To enable high‐throughput and high‐yield processing, reliable and fast in‐line characterization methods are required. The present work reports on a non‐invasive characterization technique based on intensity‐dependent photoluminescence (PL) imaging. The change in PL intensity as a function of excitation power density can be approximated by a power‐law with exponent k, which is a useful quality indicator for the perovskite layer, providing information about the relative magnitudes of radiative and non‐radiative recombination. By evaluating k‐parameter maps instead of more established PL intensity images, 2D information is obtained that is robust to optically induced artifacts such as intensity variations in excitation and reflection. Application to various half stacks of a perovskite solar cell showcase its ability to determine the importance of the interface between the charge transporting and perovskite layers. In addition, the k‐parameter correlates to the bulk passivation concentration, enabling rapid assessment of open‐circuit voltage variations in the range of 20 mV. Considering expected improvements in data acquisition speed, the presented k‐imaging method will possibly be obtained in real‐time, providing large‐area quality control in industrial‐scale perovskite PV production.

Comparison of Al/TiO2/p-Si and Al/ZnO/p-Si photodetectors

The importance of the photodetectors has grown due to their potential in the automation system and optical communications. We fabricated Al/TiO2/p-Si and Al/ZnO/p-Si Schottky-type photodetectors. TiO2 and ZnO interlayers were grown by atomic layer deposition (ALD). The photodetection properties of these devices were studied and compared by I–V and I-t measurements for various light power densities and various wavelengths. Scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) spectra were employed to determine morphological and elemental analysis of the TiO2 and ZnO interlayers. While the SEM images showed smooth surfaces, EDX spectra approved successful synthesis of the TiO2 and ZnO interlayers with good stoichiometry. The diode parameters such as ideality factor, series resistance and barrier height values were calculated and compared in detail. The responsivity and detectivity of the fabricated photodetectors were determined as a function of illumination power density and wavelength. The responsivity values of the Al/TiO2/p-Si and Al/ZnO/p-Si photodetectors were determined as 0.02 and 0.76 A/W, respectively. Both photodetectors exhibited good performance for visible light. However, Al/ZnO/p-Si photodetector reached 173.08% external quantum efficiency (EQE) for 550 nm. According to results, Al/ZnO/p-Si photodetector exhibited better detection performance than Al/TiO2/p-Si.

Biochemical reactions remote-sensitized by excitons propagating across macroscopic distances along biological fibers: Isomerization of 11-cis-retinal

Presently we report a second example of a biochemical reaction sensitized remotely by excitons (electronic excited states) efficiently transferred along intermediate filaments (IFs) over macroscopic distances. IFs are excellent conductors of energy in the form of excitons, with the efficiency of ca. 0.53 reported in vitro. Excitons were generated by visible light and propagated along Müller cell (MC) intermediate filaments, about 100 μm long. These experiments used a capillary matrix filled by MC IFs extracted from porcine retina. Excitons induced efficient isomerization of 11-cis- to all-trans-retinal, with the reaction quantum yield φcis/trans = 0.347 obtained for 11-cis-retinal concentration of 1.0 × 10−3 M (0.284 g/L) using 546 nm light at 6.87 mW/cm2 power density. Exciton quantum yield φexc at 546 nm was also measured in function of radiation power density, with nonlinearity indicative of biphotonic processes. This is the first case of biphotonic processes occurring at such low light intensities with steady-state illumination. The present results support quantum mechanism of high-contrast vision of vertebrate eyes.

Ignition of Coals with Continuous-Wave Lasers at Wavelengths of 450 and 808 nm

The kinetic and energy characteristics of the ignition of microparticle powders of coals of G (gas), Zh (fat), and K (coking) grades with a bulk density of 0.4 g/cm3 under the action of continuous-wave laser radiation at wavelengths λ = 450 and 808 nm with an exposure time of 1 s were measured. Coals were ignited only under irradiation, and the effect of flame propagation was absent. Ignition delay times were measured as a function of the radiation power density, and the critical values of the coal ignition energy density were determined. Energy consumption for the ignition of coals with radiation at λ = 808 nm was greater than that at λ = 450 nm for all grades of coals. It was established that the absorption of laser radiation by coal samples had a quantum character.

Procedure to generate a selection chart for microwave sol-gel synthesis of nanoparticles

Numerical simulation is used to compare the temperature distribution existing during microwave or conventional heating by hot oil bath of a reaction volume. The simulation is applied to the sol-gel synthesis of TiO2 nanopowders, considering temperature dependent materials parameters. A WR340-based single mode applicator operating at 2.45 GHz is considered, with a cylindrical load positioned in regions of predominant electric field. A temperature homogeneity index, defined as the ratio between the average temperature and its standard deviation at a certain time, is used to compare homogeneity of conventional and microwave heating at different power densities, from 370 to 7400 W/L. Based on that comparison, a selection chart of the more homogenous heating process as a function of power density and average temperature of the reaction volume is defined and can be used to select the experimental conditions expected to lead to a more or less homogeneous particle size of the products.A dedicated instrumented model, including three optical fibres, is developed as well, for validation purposes. Experimental validation showed a very good predictive capability of the model, with errors on estimated temperature lower than 3 °C at temperatures lower than 80 °C.

Modulating the Combinatorial Target Power of MgSnN2 via RF Magnetron Sputtering for Enhanced Optoelectronic Performance: Mechanistic Insights from DFT Studies.

The unique structural features of many ternary nitride materials with strong chemical bonding and band gaps above 2.0 eV are limited and are experimentally unexplored. It is important to identify candidate materials for optoelectronic devices, particularly for light-emitting diodes (LEDs) and absorbers in tandem photovoltaics. Here, we fabricated MgSnN2 thin films, as promising II-IV-N2 semiconductors, on stainless-steel, glass, and silicon substrates via combinatorial radio-frequency magnetron sputtering. The structural defects of the MgSnN2 films were studied as a function of the Sn power density, while the Mg and Sn atomic ratios remained constant. Polycrystalline orthorhombic MgSnN2 was grown on the (120) orientation within a wide optical band gap range of ∼2.20-2.17 eV. The carrier densities of 2.18× 1020 to 1.02 × 1021 cm-3, mobilities between 3.75 and 2.24 cm2/Vs, and a decrease in resistivity from 7.64 to 2.73 × 10-3 Ω cm were confirmed by Hall-effect measurements. These high carrier concentrations suggested that the optical band gap measurements were affected by a Burstein-Moss shift. Furthermore, the electrochemical capacitance properties of the optimal MgSnN2 film exhibited an areal capacitance of 152.5 mF/cm2 at 10 mV/s with high retention stability. The experimental and theoretical results showed that MgSnN2 films were effective semiconductor nitrides toward the progression of solar absorbers and LEDs.

Nondestructive and Quantitative Evaluation of a GaAs Epitaxial Layer Covered With a Silicon Nitride Insulating Thin Film After a Highly Accelerated Temperature and Humidity Stress With the Use of Photoreflectance Spectroscopy

We demonstrate that photoreflectance spectroscopic measurements of Franz-Keldysh oscillations are applicable to nondestructively quantify the changes in surface Fermi level and surface recombination velocity of semiconductors after reliability stress tests. The present sample, a two-layer homoepitaxial structure consisting of a top undoped GaAs epilayer and a bottom n-type GaAs epilayer, were initially covered with a silicon nitride insulating thin film. This sample was subjected to the highly accelerated temperature and humidity stress. Initially, we estimated the built-in electric field strength from the Franz-Keldysh oscillations. We found that the built-in electric field strength is enhanced after the acceleration stress. Next, we performed the numerical analysis of the built-in electric field strength as a function of probe-light power density. From the above-mentioned numerical analysis, we clarified that the surface recombination velocity of the top undoped GaAs epilayer is enhanced by a factor of two. In contrast, the surface Fermi level is hardly changed. We discuss this phenomenon from the viewpoint of the formation of the surface defects that enhance the surface recombination velocity.

Development of high-performance broadband optical detector for cryogenic to elevated operating temperature

Development of broadband photodetectors for cryogenic and elevated temperature applications has been a major concern in space science and other radiation detection technologies. With this objective TiS2-nanostructures were investigated for photodetection characteristics in the temperature range of −180 °C to 150 °C. The device was developed by depositing TiS2-nanostructures amid gold-interdigitated electrodes by drop-casting technique. The photodetection performance was investigated for 617 nm and 850 nm LEDs as a function of power density and operating temperature. It is found that as-developed photodetector can operate in the solar spectrum from 375 nm to 1050 nm. The designed photodetector is capable of detecting photons at −180 °C temperature and 0.015 mW/cm2 incident light power density with an ultra-low bias voltage (0.1 V). The operational temperature range can be further extended by optimizing the bias voltage. The device has excellent photodetection capabilities for from sub-zero temperature to elevated temperatures. The highest photocurrent of 45.22 nA is obtained at 617 nm and 0.1 V bias voltage, when the temperature is 0 °C and power density is 0.792 mW/cm2, while the highest values for photoresponsivity (8.9 × 104 A/W), quantum efficiency (1.78 × 105 A/W nm), and detectivity (1.93 × 1014 Jones) are found for 0.015 mW/cm2 power density. Optimization of the Bias-voltage optimization further improves the device performance. At −120 °C operating temperature, the fastest response (response/recovery time∼0.099 s) and highest device ON/OFF ratio of the ‘as-developed’ photodetector are recorded.

Correlation between plasma characteristics, morphology, and microstructure of sputtered CuAl alloy films with varied target geometry

The effect of target geometry on coating microstructure and morphology is correlated to changes in deposition conditions, plasma characteristics, and film growth during planar and hollow cathode sputtering. The sputtering plasma properties for the two target geometries were characterized via Langmuir probe analysis as a function of power density and Ar pressure to determine the evolution of ion density for each configuration. Films were then synthesized at the low (0.4 W cm−2) and high (1.2 W cm−2) power densities and characterized using x-ray diffraction, scanning electron microscopy, and electron backscatter diffraction to link changes in texturing, morphology, and microstructure with variations in ion density and sputtering deposition conditions caused by target geometry. It was observed that varying target geometry led to an over threefold increase in deposition rate, homologous temperature, and ion density, which altered the morphology and texture of the film without significant changes to the grain size.

Understanding Yb3+-sensitized photon avalanche in Pr3+ co-doped nanocrystals: modelling and optimization.

Among different upconversion processes where the emitted photon has higher energy than the one absorbed, photon avalanche (PA) is unique, because the luminescence intensity increases by 2-3 orders of magnitude in response to a tiny increase in excitation intensity. Since its discovery in 1979, PA has been observed in bulk materials but until recently, obtaining it at the nanoscale has been a significant challenge. In the present work, the PA phenomenon in β-NaYF4 colloidal nanocrystals co-doped with Pr3+ and Yb3+ ions was successfully observed at 482 nm (3P0 → 3H4) and 607 nm (3P0 → 3H6) under excitation at 852 nm. The impact of Pr3+ ion concentration and pump power dependence on PA behavior was investigated, i.e. PA non-linearity slopes of luminescence intensity curves as a function of pump power density as well as PA thresholds. The highest slopes, namely 8.6 and 9.0, and the smallest thresholds equal to 286 kW cm-2 and 281 kW cm-2, observed for emission bands at 607 nm and 482 nm, respectively, were obtained for NaYF4:0.5%Pr3+,15%Yb3+@NaYF4 colloidal nanocrystals. Besides experimental research, simulations of PA behavior in Pr3+, Yb3+ co-doped materials were performed based on differential rate equations describing the phenomena that contribute to the existence of PA. The influence of different processes leading to PA, e.g. the rates of nonradiative and radiative transitions as well as energy transfers, on PA performance was simulated aiming to understand their roles in this complex sensitized system.

Performance Analysis of a 4H-SiC n-p-n Phototransistor With Floating Base for Ultraviolet Light Detection

A 4H-SiC n-p-n bipolar phototransistor detector (PTD) with a floating-base configuration is fabricated and studied in this work. The PTD exhibits low dark current and high responsivity in the ultraviolet (UV) wavelength band, which results in a large photo-to-dark current ratio (PDCR). The optical gain of the PTD is found highly dependent on the incident light intensity, which is larger at high light levels. Nevertheless, at low light levels, a unity gain is obtained, which is limited by the recombination current within the emitter–base (E–B) junction. The PTD further exhibits high-temperature operation potential and a detectivity of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$7.06\times 10^{{12}}$ </tex-math></inline-formula> cm <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\cdot $ </tex-math></inline-formula> Hz <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$^{\text {1/2}}$ </tex-math></inline-formula> /W can be achieved at 150 °C. The transient response characteristics of the PTD are characterized as a function of incident power density and temperatures. It is found that optical gain and junction capacitance are both important for explaining the variation trends of response time. Finally, a demonstration board is designed and fabricated to test the potential of the SiC PTD for UV radiometer applications. When operating in active mode, the PTD circuit could exhibit reasonable linear response to incident UV power density.

Efficient Up-Conversion ZnO Co-Doped (Er, Yb) Nanopowders Synthesized via the Sol-Gel Process for Photovoltaic Applications.

In this study, undoped and (Erbium, Ytterbium) co-doped ZnO nanopowders were prepared using the sol-gel method and the supercritical drying of ethyl alcohol. Doping ZnO nanopowders were elaborated with 5 mol% of Er (5 Er: ZnO), 5 mol% of Er and 5 mol% of Yb (5 Er, 5 Yb: ZnO), and 5 mol% of Er and 10 mol% of Yb (5 Er, 10 Yb: ZnO) concentrations. The effects of the Yb concentration on the structural, morphological, photoluminescent, and electrical properties of the ZnO nanopowders were investigated. The main findings of this work were the crystallinization of all of the nanopowders in a hexagonal Wurtzite structure with a spheroidal morphology and a size of 60 nm. Hence, the doping concentration would affect the crystallinity and the morphology of the ZnO nanopowder. The UC (Up-Conversion) emissions were investigated under a 980 nm excitation. It was observed that (Er, Yb: ZnO) exhibited green, ranging between 525 nm and 550 nm and red up-converted emissions of 655 nm, due to the efficient energy transfer process between Er3+ and Yb3+. The absolute quantum yield percentage (QY %) of the doped nanopowders was measured as a function of power density at each up-converted emission. This would prove that (5 Er, 5 Yb: ZnO) had the highest QY percentage value of 6.31 ± 0.2% at a power density of 15.7 W/cm2. Additionally, it had the highest excited state lifetime for green and red emissions. Moreover, the Hall effect measures showed that the resistivity decreased while the electron mobility increased after doping, suggesting that most of rare earth ions were located in the interstitial positions. The carrier concentration increased after doping until (5 Er, 5 Yb: ZnO), suggesting that the Zn2+ ions substituted the RE3+ ions. Then, the carrier concentration decreased, suggesting that doping with higher concentrations would cause grain boundary defects. These findings would suggest that (5 Er, 5 Yb: ZnO) would have the best electrical properties and the lowest band gap energy (3.24 eV). Therefore, the presented preparation of the (Er, Yb: ZnO) nanopowders elaborated, using the sol-gel process would be a potential interesting material for UC applications.

Susceptibility of multipactor discharges near a dielectric driven by a Gaussian-type transverse rf electric field

Multipactor discharge near an rf window is a key limiting factor in high power microwave systems. In this work, we report special features of dielectric multipactor susceptibility under a Gaussian-type waveform as a function of the rf power density of the transverse rf electric field (P¯rf) and normal restoring field (Edc) via particle-in-cell (PIC) and multiple particle Monte Carlo (MC) simulations. The MC simulations show that, for a Gaussian waveform of a half peak width (Δτ), larger than Δτ/T=0.15 with T = 1 ns the rf repetition period, the susceptibility boundary is similar to that of the conventional sinusoidal waveform-driven multipactor, i.e., two inclined lines in the plane of (P¯rf,Edc). However, by decreasing Δτ, the susceptibility boundary converts to be a closed curve at Δτ/T=0.11 in the plane of (P¯rf,Edc) and further shrinks at Δτ/T=0.05. PIC simulations with a self-consistent surface and space charge effects also show a reduced Edc with increasing P¯rf when P¯rf exceeds a critical value, resulting in a closed curve in the plane of (P¯rf,Edc), and the maximum time-averaged Edc (multipactor strength) also decreases significantly with further decreasing Δτ in agreement with MC simulations. Accordingly, the fraction of the rf power density absorbed by the multipactor discharges also decreases nonlinearly with Δτ from the order of 10−2 to 10−3 (even 10−4), implying a significant improvement compared to the conventional sinusoidal waveform. The simulations also show that the multipactor susceptibility under a transverse Gaussian-type waveform for different frequencies follows the same scaling law in terms of the ratio of the electric field to the rf repetition rate.

A fundamental analysis of factors affecting chemical homogeneity in the laser powder bed fusion process

In this work a novel mathematical framework, that fully describes the fusion and vapourisation state transitions in multi-component systems, has been applied to assist in understanding the fundamental mechanisms of defect formation and chemical homogenisation in the laser powder bed fusion process (L-PBF). Specifically, the role of vapourisation and condensation of the multi-component metallic substrate is investigated to determine the importance of properly capturing the state transitions when understanding the substrate evolution. The framework is applied to a ternary metallic system; it is revealed that entrained vapour bubbles in chemically dissimilar flows promote greater homogenisation during the condensation and collapse of these bubbles when compared to non-condensing phases. It is further shown that as the laser power density is increased, there is a greater tendency for preferential element evaporation of the lighter elements; this preferential element evaporation is quantified numerically for the first time, and shown to be a non-linear function of power density.

Imaging the effect of high photoexcited densities on valley polarization and coherence in MoS2 monolayers

We have investigated the laser-induced valley polarization and coherence of encapsulated MoS2 monolayer as a function of temperature, power density, and spatial position. Besides a non-monotonic dependence on temperature, recently attributed to a dependence of the valley relaxation time on the momentum scattering rate, we observe a two-fold increase of the valley polarization when increasing the laser excitation power. We attribute this effect to a local heating induced by the energy relaxation of photoexcited excitons and to an increase of the exciton-exciton scattering rate. In contrast, only a moderate enhancement of valley coherence is observed, which exhibits a dramatic drop after further increasing the excitation power. We attribute this behaviour to the detrimental role of exciton-exciton interactions on the pure dephasing rate responsible for the loss of coherence between the valleys. This manifests itself by a strong dip in the spatial profile of the valley coherence at high photoexcited densities.

Modeling a Lossy Dieletric Polymer-based Thermoacoustic High Power Microwave Directed Energy Exposure Detection System.

Presented are design considerations for a potential detection and measurement technique that could provide operational awareness of high power microwave (HPM) directed energy weapon exposure for force health protection applications, leveraging thermoacoustic (TA) wave generation as the field interaction mechanism. The HPM electromagnetic frequency (EMF) regime, used in applications in both the counter-materiel and non-lethal counter-personnel design space, presents real-time personnel exposure warning challenges due to the potentially wide variation in time and frequency domain characteristics of the incident beam. As with other EM-thermal interactions, the thermoacoustic wave effect provides the potential to determine EM energy and power deposition without the need to measure ambient field intensity values or overload-sensitive EMF survey equipment. Following measurement of relevant EM, thermal, and elastic material property values, a carbon-filled polytetrafluoroethylene (CF-PTFE) lossy dielectric medium subject to pulsed HPM was computationally modeled using the commercial finite element method multi-physics simulation software package COMSOL. The simulation was used to explore the impacts of various material properties on TA signal output as a function of simulated incident field power density, EM frequency, and pulse length, thereby informing the selection of system components for the further development of a full TA-based HPM detection chain.

Evaluating Wind Erosion Sensitivity for Landfill Sites in New Mexico Using Fuzzy Analytical Hierarchy Process (FAHP)

The final closure veneer for municipal solid waste landfills must be designed to withstand an allowable annual soil loss from wind erosion over its design life. Veneer sensitivity to wind erosion depends on a multiplicity of intertwined variables. A Fuzzy Analytical Hierarchy Process (FAHP) is used to evaluate weightings for specific forcing function criteria to assess overall wind erosion sensitivity (WES) at current and former landfill locations based on input from multiple decision makers selected from consulting, regulatory, and academe sources. FAHP weights represent the degree of importance of a given criteria relative to an overall criterion. For WES assessment, three criteria were identified: climatic factor (CF) as a function of wind power density (WPD) and effective precipitation index (EPI), vegetation cover (VC), and soil erodibility given as a wind erodibility index (WEI). The results revealed almost equal importance for WPD and VC with WEI being the lesser important criteria. Rankings of thirteen landfill locations in New Mexico showed that Las Cruces was most susceptible to wind erosion with Los Alamos and Clines Corner being least susceptible. The assessment methodology is useful for identifying potential hot spots for wind erosion with respect to the design and maintenance of final cover for landfills.

Impact of core power density on economics of a small integral PWR

Increasing the core power density of nuclear reactors allows higher power generation from the same volume, reducing the cost of the plant. The lower power rating and higher degree of inherent safety for small modular reactors motivate exploring the highest achievable power density to improve their economics and overcome lack of economy of scale. Given the urgency to deploy carbon free energy sources in the near term, the current nuclear fuel supply must be adopted. Assuming standard 17x17 pressurized water reactor (PWR) fuel assemblies with enrichment below 5%, a parametric study on core power density of an integral PWR (iPWR) is performed. The reference core design is rated at 60 kW/L and composed of 77 reduced-height fuel assemblies. The reactivity control during normal operation is assumed to utilize soluble boron and fuel burnable poisons. The commercial STUDSVIK code package is used to design cores ranging from 20 kW/L to 170 kW/L. This range results in respective output powers between 50 and 420 MWe for an assumed 32% plant thermal efficiency. Core safety parameters, such as peaking factors, Minimum Departure from Nucleate Boiling Ratio and maximum fuel temperatures are evaluated for all designs. Simplified economic evaluation of lifetime-levelized unit costs for the fuel cycle, operation and maintenance and capital expenditures was performed as a function of power density. The relatively low core discharge burnup (32 MWD/kgU) leads to high lifetime-levelized fuel cycle unit cost for the reference core. However, increase in power density allows significant reduction in operation, maintenance and capital unit costs. Doubling power density resulted in 80% reduction in total levelized cost of electricity. The unique features of a forced circulation iPWR technology combined with compact steam generator technology could allow achieving high power densities (greater than 125 kW/L). Specific examples on relationship of cost and safety margins are also discussed.

Yb to Tb Cooperative Upconversion in Supramolecularly Assembled Complexes in a Solution

The podand-type ligand L, based on a tertiary amine substituted by three pyridyl-6-phosphonic acid functions, forms hydrated complexes with Ln3+ cations. The luminescence properties of the YbL complex were studied in D2O as a function of the pD and temperature. In basic conditions, increases in the luminescence quantum yield and the excited state lifetime of the Yb centered emission associated with the 2F5/2 → 2F7/2 transition were observed and attributed to a change in the hydration number from two water molecules in the first coordination sphere of Yb at acidic pH to a single one in basic conditions. Upon the addition of TbCl3 salts to a solution containing the YbL complex in D2O, heteropolynuclear Yb/Tb species formed, and excitation of the Yb at 980 nm resulted in the observation of the typical visible emission of Tb as a result of a cooperative upconversion (UC) photosensitization process. The UC was further evidenced by the quadratic dependence of the UC emission as a function of the laser power density.

Plasmon resonance, thermal, and optical contributions to anti‐Stokes‐to‐Stokes line strength ratios in continuous wave‐excited surface‐enhanced Raman scattering spectra of molecules at random Ag surface

AbstractSurface‐enhanced Raman scattering (SERS) by biochemically relevant organic reporter molecules, spread out over a promising localized surface plasmon resonance (LSPR) structure of randomly arranged silver nanoscale particles (AgPs) of various dimensions and shape, was induced using tightly focused continuous wave (CW) 785‐nm laser radiation, and the spectra were registered simultaneously in the anti‐Stokes and Stokes spectral ranges. The spectra were recorded as a function of the excitation laser power density in the range of their profile reproducibility. The power density dependences of the line strength ratio for three respective pairs of vibrational lines of a thiolate of 2‐nitrobenzoic acid (TNB) in SERS spectra were derived. Using these data, we specify and quantify the contributions responsible for the discrepancy between this ratio and that defined by the thermal equilibrium populations of the upper and lower vibrational levels corresponding to the Raman‐active transitions. These contributions are the following: (i) the spectral profile of an LSPR contour, (ii) local heating of the reporter molecule/AgP conjugates by the 785‐nm radiation, and (iii) optical (Raman) pumping of the upper vibrational levels of the transitions involved. The extraction of the latter contribution enabled us to estimate the cross‐sections of the TNB/AgP conjugates Raman vibrational pumping by the radiation for each of the three vibrational modes.