Spectroscopic Performance Research Articles

Investigation the Structure and Linear/Nonlinear Spectroscopic Performance of Fe:Co3O4/TiO2 Nanostructured Heterojunctions

Abstract The structure and linear/nonlinear spectroscopic performance of Fe:Co3O4/TiO2 (FCTO) nanostructured heterojunctions (HJs) were investigated. Pure TiO2 nanostructures and FCTO nanostructured HJs were synthesized by spray pyrolysis technique. The surfaces morphology of the samples was examined utilizing a scanning electron microscope. Energy-dispersive X-ray measurements were performed to confirm the content of the prepared FCTO HJs. The structures’ variations and bonding were explored with Fourier transform infrared spectroscopy. X-ray diffraction measurements were carried out to study the crystallinity, structures, and lattice parameters, revealing that the pure TiO2 nanostructures have a tetragonal crystalline structure with an anatase phase, while the Fe:Co3O4 layer possesses a cubic crystalline structure. XRD analysis also showed that the crystallite size increases from 15.9 nm (pure TiO2) to 25.4 nm (FCTO HJ). Optical performance was studied via UV-visible-NIR measurements. The optical parameters of the FCTO HJs were investigated and the nonlinear optical performance of the prepared samples was assessed. Great enhancement of the linear/nonlinear optical performance of the FCTO HJs was achieved compared with the pure TiO2 nanostructures. The results reveal that the Fe:Co3O4/TiO2 nanostructured HJs are recommended for many visible spectrum applications.

Characterization of long-term stability of thallium bromide detectors

Abstract Thallium bromide (TlBr) gamma ray detectors exhibit excellent spectroscopic performance at room temperature. Long-term stability is an essential property for the practical application of detectors. In this study, the long-term stability of the spectroscopic performance of the TlBr detectors was characterized by acquiring 137Cs gamma-ray spectra at room temperature. TlBr detectors were fabricated from zone-purified TlBr crystals by constructing Tl electrodes. The TlBr detectors demonstrated stable spectroscopic performances for 1000 h operations at room temperature without bias polarity switching. The peak positions for the 662 keV gamma rays remained within ±1% of the average values for the 1000 h measurements. The detectors exhibited energy resolutions of ≤4.0% full width at half maximum for 662 keV gamma rays for 1000 h acquisitions without pulse height corrections. These results suggest that TlBr detectors with Tl electrodes are potential gamma-ray detectors for practical applications.

Rare earth induced lattice distortion of Bi2WO6 to effectively improve photocatalytic performance: Experimental and DFT calculations

The excellent visible light photocatalytic activity of bismuth-based photocatalysts has attracted the interest of many scholars at home and abroad. In this paper, rare earth (Sm, La, Ce, Eu) doped Bi2WO6 photocatalysts were prepared by a one-step hydrothermal method using bismuth nitrate and sodium tungstate as precursors. The microstructures and spectroscopic performances of prepared materials were investigated utilizing characterization methods, such as XRD, XPS, UV–vis, TEM, and N2 adsorption-desorption, etc., and the effluent removal performances were studied by using rhodamine B as a simulated degradation dye and the photodegradation mechanism was investigated in combination with DFT calculations. XRD indicates that the rare earth doping leads to the lattice distortion of the (131) crystal surface of Bi2WO6, and the relative amount of distortion is directly proportional to the photocatalytic activity; UV–vis spectra show that the absorption edge of Bi2WO6 is obviously red-shifted with the rare earth doping, and N2 adsorption-desorption curve show that the doped rare earths make the specific surface area of the sample effectively increased. Moreover, XPS spectrum suggests that the doped rare earth Ce and Eu often exist in the form of metastable oxidation states, and the transformation between Ce3+/Ce4+ and Eu2+/Eu3+ oxidation states is easy to form impurity energy levels between Bi2WO6, which make the energy level significantly enriched to broaden the absorption range and reduce band gap width of the material. DFT calculations further indicate that the rare earths successfully replace Bi sites. One of the main reasons for the improvement of photocatalytic activity is that rare earth doping is easier to replace Bi sites, leading to increased relative aberration; another one is that the arrangement of EVB and ECB in the photocatalytic mechanism is type-II, which contributes to red-shift of absorption edge and effective separation of electron-hole pairs in the photocatalytic process, thus improving the photocatalytic activity.

Spectroscopic performance of Low-Gain Avalanche Diodes for different types of radiation

LGADs (Low-Gain Avalanche Diodes or Detectors) are a type of silicon Avalanche Photo-Diodes originally developed for the fast detection of minimum ionizing particles in high-energy physics experiments. Thanks to their fast timing performance, the LGAD paradigm enables detectors to accurately measure minimum ionizing particles with a timing resolution of a few tens of picoseconds. Such a performance is due to a thin substrate and the presence of a moderate signal gain. This internal gain of a few tens is enough to compensate for the reduced charge deposition in the thinner substrate and the noise of fast read-out systems. While LGADs are optimized for the detection of minimum ionizing particles for high-energy particle detectors, it is critical to study their performance for the detection of different types of particle, such as X-rays, gamma-rays, or alphas. In this paper, we evaluate the gain of three types of LGADs: two devices with different geometries and doping profiles fabricated by Brookhaven National Laboratory, and one fabricated by Hamamatsu Photonics with a different process.Since the gain in LGADs depends on the bias voltage applied to the sensor, pulse-height spectra have been acquired for bias voltages spanning from the depletion voltage up to the breakdown voltage. The signal-to-noise ratio of the generated signals and the shape of their spectra allow us to probe the underlying physics of the multiplication process.

Design and development of the DE-SPECT system: a clinical SPECT system for broadband multi-isotope imaging of peripheral vascular disease

Objective. Peripheral Vascular Disease (PVD) affects more than 230 million people worldwide and is one of the leading causes of disability among people over age 60. Nowadays, PVD remains largely underdiagnosed and undertreated, and requires the development of tailored diagnostic approaches. We present the full design of the Dynamic Extremity SPECT (DE-SPECT) system, the first organ-dedicated SPECT system for lower extremity imaging, based on 1 cm thick Cadmium Zinc Telluride (CZT) spectrometers and a dynamic dual field-of-view (FOV) synthetic compound-eye (SCE) collimator. Approach. The proposed DE-SPECT detection system consists of 48 1 cm thick 3D-position-sensitive CZT spectrometers arranged in a partial ring of 59 cm in diameter in a checkerboard pattern. The detection system is coupled with a compact dynamic SCE collimator that allows the user to select between two different FOVs at any time during an imaging study: a wide-FOV (28 cm diameter) configuration for dual-leg or scout imaging or a high-resolution and high-sensitivity (HR-HS) FOV (16 cm diameter) for single-leg or focused imaging. Main results. The preliminary experimental data show that the CZT spectrometer achieves a 3D intrinsic spatial resolution of <0.75 mm FWHM and an excellent energy resolution over a broad energy range (2.6 keV FWHM at 218, 3.3 keV at 440 keV). From simulations, the wide-FOV configuration offers a 0.034% averaged sensitivity at 140 keV and <8 mm spatial resolution, whereas the HR-HS configuration presents a peak central sensitivity of 0.07% at 140 keV and a ∼5 mm spatial resolution. The dynamic SCE collimator enables the capability to perform joint reconstructions that would ensure an overall improvement in imaging performance. Significance. The DE-SPECT system is a stationary and high-performance SPECT system that offers an excellent spectroscopic performance with a unique computer-controlled dual-FOV imaging capability, and a relatively high sensitivity for multi-tracer and multi-functional SPECT imaging of the extremities.

Passivation mechanism and long-term stability: Insights from SEM-EDS analysis of passivated CdZnTeSe crystal

This study investigates the efficient passivation of CdTe-based semiconductor crystals, focusing on the long-term stability and underlying mechanisms of NaOCl passivation. CdZnTeSe crystals were grown, processed, and passivated with NaOCl, and their surface characteristics were studied using SEM-EDS and XPS. The passivation was found to significantly enhance the surface resistance, with a sustained effect for more than 90 s, attributed to the formation of a tellurium oxide layer. The passivation process was further elucidated through detailed morphological and compositional analyses. The NaOCl-passivated crystals exhibited improved electrical and spectroscopic properties in radiation detection, with a prolonged stability of 60–90 days, which are longer compared to other passivants. Additionally, the feasibility of NaOCl passivation on a CdZnTeSe detector was explored, showcasing enhanced material resistance and spectroscopic performance. The study concludes with insights into the potential industrial application of NaOCl passivation for CdTe-based radiation detectors.

Crystal growth and spectroscopic performances of Dy3+:YPO4 and Dy3+/Tb3+:YPO4 crystal as potential yellow laser gain mediums

Exploring new Dy3+-doped laser gain medium is still a challenge for constructing efficient yellow solid-state laser at current stage. In this paper, high quality Dy3+:YPO4 and Dy3+/Tb3+:YPO4 crystals were grown by the high temperature solution method. The crystal structure, chemical composition, phonon energy, polarized absorption and emission spectra, fluorescence lifetime were investigated. The obtained large FWHMs (6 nm) and absorption cross-sections (3.87×10−21 cm2) of Dy3+:YPO4 and Dy3+/Tb3+:YPO4 crystals at 454 nm indicate that they can be efficiently pumped by the commercial blue laser diodes. J-O intensity (Ω2, Ω4, Ω6), fluorescence branching rate and radiative lifetime of Dy3+ ions were calculated by J-O theory. Benefiting from the appropriate phonon energy, the emission cross-section of Dy3+: YPO4 crystal at 575 nm can reach 5.04×10−21 cm2. Moreover, after co-doping Tb3+ as deactivating ion, the emission cross-section of Dy3+/Tb3+: YPO4 crystal at 575 nm was promoted to 5.98×10−21 cm2 by a resonance energy transfer process between the Dy3+-6H13/2 and Tb3+-7F4. Therefore, both Dy3+:YPO4 and Dy3+/Tb3+:YPO4 crystals are potential candidates for yellow laser gain mediums.

Graphene quantum dots–From spectroscopic performance to 3D printing applications and interaction studies with normal and cancer cells

In this study, different types of graphene quantum dots (GQDs) are investigated to understand their spectroscopic properties. Morphological and size analyses were performed. The mechanism of action of radical photopolymerization was evaluated. The obtained materials proved to be useful for developing efficient photoinitiating systems for 3D printing applications. In addition, the cytotoxicity of the GQDs was studied, and their effects on living cells were investigated. We demonstrated that GQDs can not only act as efficient photoinitiators but also as constituents of hydrogels that express very low toxicity and may interact with cells. The latter makes it possible to study them in the future as useful modern biosensors.

Does entanglement enhance single-molecule pulsed biphoton spectroscopy?

Abstract It depends. For a single molecule interacting with one mode of a biphoton probe, we show that the spectroscopic information has three contributions, only one of which is a genuine two-photon contribution. When all the scattered light can be measured, solely this contribution exists and can be fully extracted using unentangled measurements. Furthermore, this two-photon contribution can, in principle, be matched by an optimised but unentangled single-photon probe. When the matter system spontaneously emits into inaccessible modes, an advantage due to entanglement can not be ruled out. In practice, time-frequency entanglement does enhance spectroscopic performance of the oft-studied weakly-pumped spontaneous parametric down conversion (PDC) probes. For two-level systems and coupled dimers, more entangled PDC probes yield more spectroscopic information, even in the presence of emission into inaccessible modes. Moreover, simple, unentangled measurements can capture between 60% and 90% of the spectroscopic information. We thus establish that biphoton spectroscopy using source-engineered PDC probes and unentangled measurements can provide tangible quantum enhancement. Our work underscores the intricate role of entanglement in single-molecule spectroscopy using quantum light.

Enhancing predictive performance for spectroscopic studies in wildlife science through a multi-model approach: A case study for species classification of live amphibians.

Near infrared spectroscopy coupled with predictive modeling is a growing field of study for addressing questions in wildlife science aimed at improving management strategies and conservation outcomes for managed and threatened fauna. To date, the majority of spectroscopic studies in wildlife and fisheries applied chemometrics and predictive modeling with a single-algorithm approach. By contrast, multi-model approaches are used routinely for analyzing spectroscopic datasets across many major industries (e.g., medicine, agriculture) to maximize predictive outcomes for real-world applications. In this study, we conducted a benchmark modeling exercise to compare the performance of several machine learning algorithms in a multi-class problem utilizing a multivariate spectroscopic dataset obtained from live animals. Spectra obtained from live individuals representing eleven amphibian species were classified according to taxonomic designation. Seven modeling techniques were applied to generate prediction models, which varied significantly (p < 0.05) with regard to mean classification accuracy (e.g., support vector machine: 95.8 ± 0.8% vs. K-nearest neighbors: 89.3 ± 1.0%). Through the use of a multi-algorithm approach, candidate algorithms can be identified and applied to more effectively model complex spectroscopic data collected for wildlife sciences. Other key considerations in the predictive modeling workflow that serve to optimize spectroscopic model performance (e.g., variable selection and cross-validation procedures) are also discussed.

Bishydrazone ligand and its Zn-complex: synthesis, characterization and estimation of scalability inhibition mitigation effectiveness for API 5L X70 carbon steel in 3.5% NaCl solutions.

Bishydrazone ligand, 2,2'-thiobis(N'-((E)-thiophen-2-ylmethylene) acetohydrazide), H2TTAH and its Zn- complex were prepared and characterized through elemental analysis and various spectroscopic performances as well as (IR, 1H and 13C NMR, mass and (UV-Vis) measurements. The synthesized complex exhibited the molecular formula [Zn2(H2TTAH)(OH)4(C5H5N)3C2H5OH] (Zn-H2TTAH). To assess their potential as anti-corrosion materials, the synthesized particles were assessed for their effectiveness for API 5L X70 C-steel corrosion in a 3.5% NaCl solution using electrochemical methods such as potentiodynamic polarization (PP) and electrochemical impedance spectroscopy (EIS). Additionally, X-ray photoelectron spectroscopy (XPS) was employed to examine the steel surface treated with the tested inhibitors, confirming the establishment of an adsorbed protecting layer. The results obtained from the PP plots indicated that both H2TTAH and Zn-H2TTAH act as mixed-type inhibitors. At a maximum concentration of 1 × 10-4 M, H2TTAH and Zn-H2TTAH exhibited inhibition efficiencies of 93.4% and 96.1%, respectively. The adsorption of these inhibitors on the steel surface followed the Langmuir adsorption isotherm, and it was determined to be chemisorption. DFT calculations were achieved to regulate the electron donation ability of H2TTAH and Zn-H2TTAH molecules. Additionally, Monte Carlo (MC) simulations were conducted to validate the adsorption configurations on the steel surface and gain insight into the corrosion inhibition mechanism facilitated by these molecules.

Multi-target Pulsed Laser Deposition (PLD) Technique for the growth of μm-to-nm scale Photo-active Thin-film Coatings

There has been an unprecedented increase in the growth of photonic components over the last 25 years based on different photonic materials; each having structural/functional limitation in integrated devices. The challenge is that the semiconductors are grown inside MBE chambers, whereas the polymeric waveguides are fabricated by spin-coating. By comparison, glass and crystal-based materials are processed via sputtering and sol-gel techniques. None of these materials processing techniques, therefore, are compatible for a single-step device fabrication, due to the incompatibilities of chemical and physical properties of individual materials. A solution for overcoming the materials limitation is to develop a multi-materials deposition chamber which allows sequential/heterostructure growth on a substrate, without compromising the structural, spectroscopic, and device performances. The rare-earth-ion doped glass- and crystal-based devices are pumped with semiconductor lasers, suggesting that the glass-semiconductor devices might perform better when structurally integrated which may also help in reducing the pump-power for achieving efficient population inversion. We explain the applications of PLD for controlling the structure of thin-films grown on inorganic and metallic substrates for photonic device and photo-active coatings for biological applications, respectively. Examples of materials deposited on dissimilar substrates are discussed with applications such as photonic devices and photo-bioactive surfaces for sensing.

Diffractive order Mueller matrix ellipsometry for the design and manufacture of polarization beam splitting metasurfaces.

Optical metasurface technology promises an important potential for replacing bulky traditional optical components, in addition to enabling new compact and lightweight metasurface-based devices. Since even subtle imperfections in metasurface design or manufacture strongly affect their performance, there is an urgent need to develop proper and accurate protocols for their characterization, allowing for efficient control of the fabrication. We present non-destructive spectroscopic Mueller matrix ellipsometry in an uncommon off-specular configuration as a powerful tool for the characterization of orthogonal polarization beam-splitters based on a-Si:H nanopillars. Through Mueller matrix analysis, the spectroscopic polarimetric performance of the ±1 diffraction orders is experimentally demonstrated. This reveals a wavelength shift in the maximum efficiency caused by fabrication-induced conical pillars while still maintaining a polarimetric response close to ideal non-depolarizing Mueller matrices. We highlight the advantage of the spectroscopic Mueller matrix approach, which not only allows for monitoring and control of the fabrication process itself, but also verifies the initial design and produces feedback into the computational design.

Design study and spectroscopic performance of SOI pixel detector with a pinned depleted diode structure for X-ray astronomy

We have been developing silicon-on-insulator (SOI) pixel detectors with a pinned depleted diode (PDD) structure, named “XRPIX”, for X-ray astronomy. The PDD structure is formed in a thick p-type substrate, to which high negative voltage is applied to make it fully depleted. A pinned p-well is introduced at the backside of the insulator layer to reduce a dark current generation at the Si-SiO2 interface and to fix the back-gate voltage of the SOI transistors. An n-well is further introduced between the p-well and the substrate to make a potential barrier between them and suppress a leakage current. An optimization study on the n-well dopant concentration is necessary because a higher dopant concentration could result in a higher potential barrier but also in a larger sense-node capacitance leading to a lower spectroscopic performance, and vice versa. Based on a device simulation, we fabricated five candidate chips having different n-well dopant concentrations. We successfully found out the best n-well design, which suppressed a large leakage current and showed satisfactory X-ray spectroscopic performance. Too low and too high n-well dopant concentration chips showed a large leakage current and degraded X-ray spectroscopic performance, respectively. We also found that the dependency of X-ray spectroscopic performance on the n-well dopant concentration can be largely explained by the difference in sense-node capacitance.

Spectroscopic properties of Yb3+/Ho3+:Lu1.5Y1.5Al5O12 crystals

Yb3+ and Ho3+ co-doped Lu1.5Y1.5Al5O12 (abbr. as Yb/Ho:LuYAG) crystals were grown using Czochralski method, and their spectroscopic properties were systematically studied. The effect of the doping concentration of Yb3+ on the spectroscopic performances were discussed comprehensively, and it was found that the 1 at% Ho3+, 5 at% Yb3+:LuYAG crystal shows better spectral properties. For example, the sensitized ion Yb3+ can transfer 64.9 % of its own energy to Ho3+ to achieve effective pumping of Ho3+ and thus obtain the intense infrared emissions with peak at 2090 nm. Furthermore, under the pumping of 937 nm, the green, red and infrared waveband emissions with peaks at 558, 667 and 756 nm were observed in it, and the red emission is much stronger than the other two emissions. The results show that 1 at% Ho3+, 5 at% Yb3+:LuYAG crystals are excellent gain media for realizing up-converted visible lasers and infrared lasers in the ∼2.09 µm band.

Frontiers of Deep-Red Emission of Mn4+ Ions with Ruddlesden-Popper Perovskites.

It is well-known that the chemical composition of the host material significantly affects the spectroscopic performance of transition metal ions. However, it is worth noting that also the structure and symmetry of crystallographic sites play significant roles in transition metal ion luminescence. In this study, we demonstrate three perovskite structures of strontium titanate forming so-called Ruddlesden-Popper phases doped with Mn4+ ions. The observed reduction in the average Ti4+-O2- distance in the series SrTiO3-Sr2TiO4-Sr3Ti2O7 allowed for a record-breaking shift in the spectral position of Mn4+ emission band with a maximum of around 734 nm and led to an improvement of the already impressive thermometric performance of SrTiO3:Mn4+ in ratiometric and lifetime-based approaches. This research encourages a further search for structures that, with the help of the developed correlations between structural and optical properties, could lead to the discovery of phosphors beyond the limits established so far.

Characterization of a 5 mm thick CZT-Timepix3 pixel detector for energy-dispersive γ-ray and particle tracking

The present manuscript describes a comprehensive characterization of a novel highly segmented 5 mm CZT sensor attached to Timepix3. First, the sensor’s IV curve was measured and basic sensor characterization was done with laboratory γ-radiation sources. The sensor resistivity was determined to be (0.155± 0.02) GOhm · cm. The sensor showed decent homogeneity, both for the per-pixel count rate and electron mobility-lifetime product μ e τ e. The latter was measured to be = 1.3 × 10−3 cm2/V with a standard deviation σ = 0.4 × 10−3 cm2/V describing the dispersion of values for different pixels. The basic sensor characterization is complemented by measurements at grazing angle in a 120 GeV/c at the CERN’s Super Proton Synchrotron. The penetrating nature of these particles together with the pixelation of the sensor allows for a determination of the charge collection efficiency (CCE), as well as charge carrier drift properties (drift times, lateral charge cloud expansion) as a function of the interaction depths in the sensor. While CCE drops by 30%–40% towards the cathode side of the sensor, from the drift time dependency on interaction depth, the electron mobility μ e was extracted to be (944.8 ± 1.3) cm2/V/s and τ e = (1.38 ± 0.31) μs. The spectroscopic performance was assessed in photon fields and extracted from energy loss spectra measured at different angles in the pion beam. While at photon energies below 120 keV incomplete charge collection leads to an underestimation of the photon energy when irradiated from the front-side, at higher energies the relative energy resolution was found to be ∼4.5%, while a relative energy resolution of ∼7.5% was found for the particle energy loss spectra. It is shown that the drift time information can be used to reconstruct particle interactions in the sensor in 3D, providing a spatial resolution of σ xyz = 241 μm within the sensor volume and a particle trajectory measurement precision Δxyz = 100 μm, at a distance of 1 m from the sensor. We demonstrate by measurement with a 22Na source, that the energy resolution combined with the 3D reconstruction allows for detection of γ-ray source location and polarity using Compton scattering within the sensor (Compton camera and scatter polarimeter).

Spectroscopic properties of Pr:PbF2 crystal with different doping concentration

Three Pr:PbF2 single crystals with different doping concentrations (0.1, 0.5 and 1.0 at.%) have been detailed investigated to figure out the effect of doping concentration on spectroscopic properties for the first time. The XRD study shows the crystals belong to the cubic system and the lattice parameter of 1.0 at.% Pr:PbF2 crystal is 5.9336 Å. The maximum phonon energy of three crystals was speculated as low as 259 cm−1 through Raman spectra. The absorption and fluorescence spectra of the Pr:PbF2 crystals with different doping levels were recorded and analyzed with the J-O theory. The maximum absorption cross-section at 443 nm and maximum emission cross-section at 482 nm can be obtained as 1.00 × 10−20 cm2 and 1.08 × 10−20 cm2 in 1.0 at.% Pr:PbF2 crystal, respectively. The gain cross-sections of the Pr:PbF2 crystals become positive in a range of 482–497 nm once the population inversion level reaches 30 %. The maximum fluorescence lifetime of 3P0 energy level was found as 33 μs in 0.1 at.% Pr:PbF2 crystal. On the whole, the spectroscopic performance of Pr: PbF2 crystal would be improved by increasing the Pr3+ doping level appropriately.

Toward Understanding the Spectroscopic Performance and Charge Transport Mechanisms of Methylammonium Lead Tribromide Perovskite X- and γ-Rays Detectors

Toward Understanding the Spectroscopic Performance and Charge Transport Mechanisms of Methylammonium Lead Tribromide Perovskite X- and <i>γ</i>-Rays Detectors

Influence of high fluence heavy ion irradiation on the performance of single crystal diamond detectors

Radiation detectors based on diamond are highly favored for particle physics research due to their superior radiation hardness. In this work, the performance of single crystal diamond detectors under high fluence heavy ion radiation has been investigated. After irradiation by Fe13+ and Xe20+ ion beams with a high particle fluence of 1.2 × 1015 cm-2, the properties of unirradiated and irradiated intrinsic single crystal chemical vapor deposition (CVD) diamond detectors are compared by means of the spectroscopic energy resolution, charge collection efficiency (CCE), mobility-lifetime (μτ) product and time response using a 241Am alpha (α) particle source. The experimental results of the unirradiated sample with respect to I-V dark current levels, showed an ohmic behaviour of the Al and Cr/Au contact, CCE of 100%, fast response with a rise time of 750 ps and a fall time of 600 ps as well as drift velocities of 6.67 × 104 m/s and 4.72 × 104 m/s for holes and electrons respectively. In the case of the irradiated samples, the CCE, μτ product and time response pulse amplitude of holes and electrons were all degraded, indicating that high density trappings for both kinds of carriers were created under the diamond crystal surface and the trapping probability of holes and electrons was equal, which was different from the previous reports in the literature where only higher trapping probability of holes were observed under heavy ions irradiation. In particular, the spectroscopic performance as well as μτ product of holes and electrons in Fe13+ irradiated sample decreased more than those in Xe20+ irradiated sample, which implied that the recombination of electrons and holes increased in Fe13+ irradiated sample with greater penetration depth than that in Xe20+ irradiated sample when radiation fluence was up to 1015 cm-2, despite the lower density of lattice vacancies in Fe13+ irradiated sample. Moreover, the rise time of holes was slightly different, but the drift velocity was basically the same as that of the unirradiated sample, and so was that of the electrons. Anyway, the presented results showed that the diamond detectors irradiated by heavy ions at a high fluence of 1015 cm-2 still retained their good spectroscopic and very fast time response properties.