Semiconductor Radiation Detectors Research Articles

Effects of Intrinsic Defects on the Carrier Lifetime in CdZnTe: Insights from Ab Initio Calculations.

CdZnTe (CZT) has garnered substantial attention due to its outstanding performance in room-temperature semiconductor radiation detectors, where carrier transport properties are critical for assessing the detector performance. However, due to the complexities of crystal growth, CZT is prone to defects that affect carrier lifetime and mobility. To investigate how defects affect nonequilibrium carrier transport, nonadiabatic molecular dynamics (NAMD) is employed to examine six types of intrinsic defects and their impact on electron-hole (e-h) recombination. The findings reveal that Te substitution at the Cd site (TeCd) and Te interstitial (Tei) defects expedite recombination by introducing intermediate energy levels. The coupling of new energy levels in Te vacancy (VTe) with the conduction band minimum (CBM) slows down electron release and results in an extended recombination time. Cd substitution at the Te site (CdTe) and Cd interstitial (Cdi) defects enhance nonadiabatic coupling (NAC) to accelerate the recombination. In contrast, Cd vacancy (VCd) diminishes NAC through weakening carrier coupling with high-frequency phonons and leads to a deceleration of the recombination rate. Overall, the intrinsic defects may change electron structures to vary NAC, which is critical for the recombination rate. It is believed that this research may benefit the understanding of defects on the carriers' lifetime in CZT and provide hints for further optimizing the performance of CZT material in nuclear radiation detection.

Interface enhancement effect: SnO2/CsPbBr3 hetero-junction for improve nuclear radiation detection performance and stability

The CsPbBr3 single crystal detector emerges as a highly promising candidate among semiconductor nuclear radiation detectors, which exhibits an extensive potential application across a multitude of critical domains, particularly in nuclear physics, nuclear energy, nuclear medicine, etc. However, the polarization problem has limited the application and development of CsPbBr3 detectors and has even posed a significant hindrance to their practical implementation. In this paper, a pre-designed SnO2/CsPbBr3 hetero-junction was meticulously engineered at the interface of the Ti/CsPbBr3/Ti detector, aiming to solve the polarization problem. This paper investigates the effects of the SnO2/CsPbBr3 hetero-junction on the electrical characteristics, detection performance, and long-term stability of the detector. The final results demonstrated that the SnO2/CsPbBr3 hetero-junction had multiple beneficial effects on the CsPbBr3 detector. On the one hand, the SnO2/CsPbBr3 hetero-junction exhibited superior electron extraction efficiency when compared to the Ti/CsPbBr3 interface. On the other hand, the SnO2 layer played a crucial role in preventing the migration of ions from the CsPbBr3 crystal to the interface, as well as in blocking the permeation of atmospheric and moisture elements from the detector surface to the interface. Consequently, the SnO2/CsPbBr3 hetero-junction detector exhibited superior detection performance and enhanced long-stability when compared to the Ti/CsPbBr3/Ti detector. After the interface enhancement, the SnO2/CsPbBr3 hetero-junction detector achieved an improved energy resolution of 13.59% at an electric field of 6000 V/cm and maintained a stable energy resolution of approximately 24 ± 5% at 3000 V/cm for over 12 h. The study of the SnO2/CsPbBr3 hetero-junction detector in this work provided a new perspective for enhancing the detection performance and ensuring the long-term stability of CsPbBr3-based detectors.

Selenophosphate Pb2P2Se6 Single Crystals Growth by Chemical Vapor Transport (CVT) Method for Radiation Detection.

The heavy metal selenophosphate Pb2P2Se6 emerges as a promising room-temperature X-ray/γ-ray detectors due to its high resistivity, robust radiation-blocking capability, and outstanding carrier mobility-lifetime product, etc. However, the high activity of phosphides poses significant impediment to the synthesis and single crystal growth. In this work, we have prepared high-quality Pb2P2Se6 single crystals with using the chemical vapor transport (CVT) method. The XRD analysis combined with EDS result confirmed the uniform composition of the resulting as-grown single crystals, while UV-Vis-NIR transmittance spectra revealed the bandgap of 1.89 eV. Selected area electron diffraction patterns indicated the crystal belonged to the P21/c(14) space group. Additionally, the Au/Pb2P2Se6/Au device is fabricated, which exhibits a robust X-ray response with a sensitivity of 648.61 μC Gy-1 cm-2 at 400 V mm-1 under 50 kVp. Notably, the device also excels in alpha particle detection, boasting a resolution of ~14.48 % under a bias of 400 V bias. The hole mobility-lifetime product (μτ)h of Pb2P2Se6 is estimated to be ~2.58×10-5 cm2 V-1. The results underscore potential applications of Pb2P2Se6 crystal is in the field of the semiconductor radiation detectors.

Review on high spatial resolution dosimetry with pixelated semiconductor detectors for radiation therapy

Current and emerging radiation therapy treatment techniques are characterized by complex and spatially non-uniform dose distributions with steep dose gradients delivered through high-precision dose placement with small radiation fields. Such approaches necessitate advanced verification tools. For accurate dose profile representation in stereotactic radiation therapy using megavoltage X-rays, the Nyquist theorem places the minimum sampling step as 2.5 mm that determines the required spatial resolution of the detectors for dose verification. For techniques such as micro- and mini-beam radiotherapy, micron-scale sampling is required, and sub-millimeter for particle therapy. Silicon semiconductor detectors provide the possibility of producing small sensitive volumes (including in arrays) without compromising mechanical robustness or sensitivity, therefore allowing for high spatial resolution dosimetry. They exhibit many properties of an ideal detector, while the properties of silicon detectors known to negatively influence response can be compensated for and minimized. As such, this work reviews the current status of semiconductor radiation detectors providing dose sampling by diodes with submillimeter sensitive volumes and a pitch of 2.5 mm or smaller for relative dosimetry in X-ray and electron external beam radiation therapy, brachytherapy, microbeam radiation therapy, proton, and heavy ion therapy. The following types of devices are discussed in this work, including commercial systems and those under development: one-dimensional and two-dimensional pixelated arrays (monolithic and single diode based).

A strategy for estimating radiation dose to the blood in outpatient settings in differentiated thyroid cancer therapy with 131I-NaI.

Although standard operational procedures for pre-therapeutic dosimetry already exist for the determination of the maximum safe activity to treat differentiated thyroid cancer patients, empiric activity administration of 131I is still the most frequent way of treatment. In this way, the absorbed dose to the blood/bone marrow remains unknown. In this work, we present a strategy to estimate radiation dose to the blood in an outpatient setting. A mobile application was developed, which together with an off-the-shelf compact semiconductor radiation detector allows the determination of whole-body time-integrated activity coefficients. The methodology was tested in a cohort of 79 differentiated cancer patients who received therapeutic 131I activities. Post-therapeutic whole-body time-integrated activity coefficients were compared against pre-therapeutic estimates in a subset of 13 patients. The 95% limits of agreement between pre whole-body and post whole-body time integrated activity coefficients were [-14.4; 6.6] h when considering outliers and [-6.2; 3.6] h without outliers. A high dispersion in blood dose coefficients was found, with a four-fold difference between the highest and lower values. Blood doses were significantly higher for patients treated with dosimetrically guided activities than for empirical activities (median dose=118vs. 49cGy, respectively). Blood dose coefficients were significantly lower for patients prepared with recombinant human thyroid stimulating hormone (rhTSH) than for patients prepared with thyroid hormone withdrawal. A low correlation between blood dose and administered activity was found in empirically treated patients (R2=0.26). We successfully implemented a post-therapeutic internal dosimetry methodology for differentiated thyroid cancer therapy with 131I, which allows to estimate dose to the blood from outpatient measurements with mobile devices. The proposed methodology avoids the need of daily visits to the nuclear medicine department, thus reducing the burden for the patient and for the staff.

Modeling and Bulk Characterization of 4HSIC Radiation Detector in Sentaurus TCAD Simulation Environment

This paper gives an insight into the need for radiation detection and the most commonly flexible and efficient radiation detector. It also examines bulk characteristics of 4H-SiC semiconductor radiation detector with Ni and Ti as metals for the contact. Bulk characterization of the device, including: doping concentration, electrons and holes behaviors, space charge and current densities were carried out. The modeling is conducted using Sentaurus Technology Computer Aided Design (TCAD) to examine charge transport in bulk 4HSiC material. Data obtained were further analyzed through Sentaurus visual, sentaurus Techplot and Excel to clearly determine the characteristics of the device. It is observed that when the semiconductor and metal are in contact, the Fermi-level is established where the doping concentration varied with either magnitude of the doping concentration or nature of the dopant. Similarly, Schottky and ohmic contacts and temperature effect were observed from the device characteristics which demonstrate that, the detector can withstand a temperature from the range of 100K to 700K in no fluctuating state.

A physics based machine learning model to characterize room temperature semiconductor detectors in 3D

Room temperature semiconductor radiation detectors (RTSD) for X-ray and γ\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\gamma$$\\end{document}-ray detection are vital tools for medical imaging, astrophysics and other applications. CdZnTe (CZT) has been the main RTSD for more than three decades with desired detection properties. In a typical pixelated configuration, CZT have electrodes on opposite ends. For advanced event reconstruction algorithms at sub-pixel level, detailed characterization of the RTSD is required in three dimensional (3D) space. However, 3D characterization of the material defects and charge transport properties in the sub-pixel regime is a labor intensive process with skilled manpower and novel experimental setups. Presently, state-of-art characterization is done over the bulk of the RTSD considering homogenous properties. In this paper, we propose a novel physics based machine learning (PBML) model to characterize the RTSD over a discretized sub-pixelated 3D volume which is assumed. Our novel approach is the first to characterize a full 3D charge transport model of the RTSD. In this work, we first discretize the RTSD between a pixelated electrodes spatially into 3 dimensions—x, y, and z. The resulting discretizations are termed as voxels in 3D space. In each voxel, the different physics based charge transport properties such as drift, trapping, detrapping and recombination of charges are modeled as trainable model weights. The drift of the charges considers second order non-linear motion which is observed in practice with the RTSDs. Based on the electron–hole pair injections as input to the PBML model, and signals at the electrodes, free and trapped charges (electrons and holes) as outputs of the model, the PBML model determines the trainable weights by backpropagating the loss function. The trained weights of the model represents one-to-one relation to that of the actual physical charge transport properties in a voxelized detector.

Radiation hardness of self-powered Si/SiC heterojunction detector under neutron irradiation

When typically confronted with harsh environments in space, semiconductor radiation detectors with low-power consumption and long service life are preferred. To address this concern, a novel Si/SiC heterojunction detector is proposed in this paper. At a neutron irradiation fluence of 1 × 1012 cm−2, the detector has a charge collection efficiency of 96.2% and an energy resolution of 0.95% at 10 V bias at 243Am-244Cm alpha particle detection. It can maintain a charge collection efficiency of 44.2% in the self-powered mode. The detector's performance is improved significantly using the heterojunction structure, extending its carrier lifetime. Due to its exceptional performance in sustaining high charge collection efficiency at low bias or even in self-powered mode following neutron irradiation, the Si/SiC heterojunction detector has been established as a promising option for space radiation detection.

Identifying Defects without a priori Knowledge in a Room-Temperature Semiconductor Detector Using Physics Inspired Machine Learning Model.

Room-temperature semiconductor radiation detectors (RTSD) such as CdZnTe are popular in Computed Tomography (CT) imaging and other applications. Transport properties and material defects with respect to electron and hole transport often need to be characterized, which is a labor intensive process. However, these defects often vary from one RTSD to another and are not known a priori during characterization of the material. In recent years, physics-inspired machine learning (PI-ML) models have been developed for the RTSDs which have the ability to characterize the defects in a RTSD by discretizing it volumetrically. These learning models capture the heterogeneity of the defects in the RTSD-which arises due to the fabrication process and the energy bands of elements in the RTSD. In those models, the different defects of RTSD-trapping, detrapping and recombination for electrons and holes-are present. However, these defects are often unknown. In this work, we show the capabilities of a PI-ML model which has been developed considering all the material defects to identify certain defects which are present (or absent). Additionally, these models can identify the defects over the volume of the RTSD in a discretized manner.

Preface

It is a matter of great pleasure for the organizers to bring out the Conference proceedings of the 6th National Conference on Advanced Materials and Radiation Physics (AMRP-2023) in Journal of Physics: Conference Series. The 6th National Conference on Advanced Materials and Radiation Physics (AMRP-2023) was held during May 18-19, 2023 through HYBRID Mode at Sant Longowal Institute of Engineering and Technology, Longowal, Punjab (INDIA). The AMRP-2023 conference is an important event that brings academics and researchers from all over India to share their professional experiences, expand their professional knowledge and receive updates on the latest advances in the field of advanced materials and radiation Physics.Materials science is an interdisciplinary field which deals with the discovery and design of new materials involving the study of materials through the materials paradigm (synthesis, structure, properties and performance). The subject covers a broad spectrum of materials science research including functional materials, synthesis and processing, theoretical analyses, characterization and properties of materials. Emphasis is also placed on the interdisciplinary nature of materials science and issues at the forefront of the field, such as energy and environmental issues, as well as medical and bioengineering applications are also discussed.The Radiation Physics is highly multidisciplinary in nature and is now the backbone of the nuclear medical diagnostics. The radiation physics research covers many areas of radiation imaging techniques, fundamental studies of semiconductor radiation detectors, detector materials, radiation interaction with matter and medical physics which aims to improve knowledge and methods in the field of radiation physics and radiation dosimetry, in order to develop new radiation measurement instruments and methods for applications in research, industry and medicine.In this conference more than 150 researchers from reputed universities/institutes have shown interest in hybrid mode participation. The conference included one key note address, four plenary talks, six invited talks, and presentation of more than 130 contributed papers via online & offline mode on different aspects of the conference theme. We extend our sincere gratitude to all the authors who submitted their papers to the AMRP conference. We also like to express our great appreciation to the Keynote, plenary and invited speakers.We are thankful to Institute administration for extending all support and motivation to organize this conference. On behalf of the Conference Organizing Committee, we would like to thank the referees for their efficient and thoughtful actions. We are grateful to the members of the Organising Committee for their efforts in making and shaping the program for AMRP 2023. Particularly, we acknowledge the publishing support from the members of Journal of Physics: Conference Series. We hope that the future AMRP will be as successful and stimulating, as indicated with the contributions presented in this volume.Organising Committee AMRP-2023List of Organising Committee is available in this Pdf.

A review on emerging materials with focus on BiI3 for room-temperature semiconductor radiation detectors

A review on emerging materials with focus on BiI3 for room-temperature semiconductor radiation detectors

Extreme γ-Ray Radiation Tolerance of Spectrometer-Grade CsPbBr3 Perovskite Detectors.

The perovskite compound CsPbBr3 has recently been discovered as a promising room-temperature semiconductor radiation detector, offering an inexpensive and easy-to-manufacture alternative to the current benchmark material Cd1-x Znx Te (CZT). The performance of CsPbBr3 sensors is evaluated under harsh conditions, such as high radiation doses often found in industrial settings and extreme radiation in space. Results show minimal degradation in detector performance after exposure to 1Mrad of Co-60 gamma radiation, with no significant change to energy resolution or hole mobility and lifetime. Additionally, many of the devices are still functional after being exposed to a 10Mrad dose over 3 days, and those that do not survive can still be refabricated into working detectors. These results suggest that the failure mode in these devices is likely related to the interface between the electrode and material and their reaction, or the electrode itself and not the material itself. Overall, the study suggests that CsPbBr3 has high potential as a reliable and efficient radiation detector in various applications, including those involving extreme fluxes and energies of gamma-ray radiation.

Development of robust perovskite single crystal radiation detectors with high spectral resolution through synergetic trap deactivation and self‐healing

AbstractOrganic–inorganic halide perovskite single crystals (SCs) are promising materials for detecting ionizing radiation owing to their outstanding photoelectric conversion capability and inexpensive solution processability. However, the accuracy and stability of the detectors have been limited due to the charge traps and defects in SCs, especially when operated under high‐precision photon‐counting mode for energy spectrum acquisition. Here, we proposed a trap freezing deactivation route, which obviously suppressed dark current and noise by up to 97% and 92%, respectively. Furthermore, the bulk ion migration effect was essential for the ability to instantly self‐heal defects induced by radiation damage at temperatures down to −30°C. Consequently, the detector exhibits a record high energy resolution of 7.5% at 59.5 keV for 241Am γ‐ray source, which is the best solution‐processed semiconductor radiation detectors at the same energy range. In addition, the detector maintains over 90% of its initial performance after 9 months of storage when tested in the air. Our results will represent a revision of the paradigm that high‐spectral‐resolution and robust radiation detectors can only be realized with high temperature grown inorganic semiconductor single crystals.image

High-Resolution Alpha Spectrometry Using 4H-SiC Detectors: A Review of the State-of-the-Art

Silicon Carbide (SiC) semiconductor radiation detectors were first demonstrated in 1957, however, meaningful progress was delayed until the mid-1990s when high-quality epitaxially-grown SiC became available. Rapid progress ensued, and detection of alpha particles, gamma and X-rays, protons, fission fragments, heavy ions, beta particles, minimum-ionizing particles, and neutrons were all demonstrated. In the case of alpha-particle detection and spectrometry, the obtainable energy resolution is dependent on the design characteristics of the SiC detector as well as on the material and electronic properties of the SiC material. In this paper, we review the history of SiC alpha-particle detector development as well as the factors affecting detector performance and the prospects for further improvements. Detector design factors, including active-volume and entrance-window effects, are discussed in detail. Materials and electronic factors that influence the quality of alpha-particle detection are also discussed. These factors include SiC lattice defects, charge-carrier mobility, charge trapping, and the energy required to produce an electron-hole pair. Since the first demonstration of alpha-particle spectrometry, SiC detectors have evolved to the point that an energy resolution of 0.29% (15.9 keV FWHM for 5485.7-keV <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">241</sup> Am alpha particles) has been reported. This resolution is comparable to the best obtainable with Silicon alpha-particle detectors. The prospects for further improvements in alpha spectrometry with SiC detectors are also discussed.

Detector-grade perovskite single-crystal wafers via stress-free gel-confined solution growth targeting high-resolution ionizing radiation detection

Solution-processed organic‒inorganic halide perovskite (OIHP) single crystals (SCs) have demonstrated great potential in ionizing radiation detection due to their outstanding charge transport properties and low-cost preparation. However, the energy resolution (ER) and stability of OIHP detectors still lag far behind those of melt-grown inorganic perovskite and commercial CdZnTe counterparts due to the absence of detector-grade high-quality OIHP SCs. Here, we reveal that the crystallinity and uniformity of OIHP SCs are drastically improved by relieving interfacial stress with a facial gel-confined solution growth strategy, thus enabling the direct preparation of large-area detector-grade SC wafers up to 4 cm with drastically suppressed electronic and ionic defects. The resultant radiation detectors show both a small dark current below 1 nA and excellent baseline stability of 4.0 × 10−8 nA cm−1 s−1 V−1, which are rarely realized in OIHP detectors. Consequently, a record high ER of 4.9% at 59.5 keV is achieved under a standard 241Am gamma-ray source with an ultralow operating bias of 5 V, representing the best gamma-ray spectroscopy performance among all solution-processed semiconductor radiation detectors ever reported.

Laser Scribing for Electrode Patterning of Perovskite Spectrometer-Grade CsPbBr3 Gamma-ray Detectors

Making semiconductor radiation detectors that work at room temperature relies heavily on the deposition and pixelation of electrodes. Electrode patterning of perovskite solar cells widely implements laser scribing techniques, which is a convenient, scalable, and inexpensive technique. However, this method has not found its application in radiation detector patterning yet, and the question whether laser scribing can achieve high-quality patterns with minimum damage to a detector crystal and low interpixel cross-talk remains largely unanswered. To prove that laser scribing is a practical method for electrode patterning on perovskite CsPbBr3 detectors, we use the material to create a variety of patterns. A very low lateral leakage current (60 nA at 10 V) and high mobility-lifetime product (9.7(3) × 10-4 cm2/V) were observed between the pixel and the guard ring in tests of single-pixel devices with a separation of 200 or 100 μm between the central electrode and the guard ring. The 122 and 136 keV photopeaks in 57Co gamma-ray spectra were very well resolved with an energy resolution of up to 6.1% at 122 keV. A further reduction in gap size to 50 μm is conceivable, but more process optimization is needed.

Learning-based physical models of room-temperature semiconductor detectors with reduced data

Room-temperature semiconductor radiation detectors (RTSD) have broad applications in medical imaging, homeland security, astrophysics and others. RTSDs such as CdZnTe, CdTe are often pixelated, and characterization of these detectors at micron level can benefit 3-D event reconstruction at sub-pixel level. Material defects alongwith electron and hole charge transport properties need to be characterized which requires several experimental setups and is labor intensive. The current state-of-art approaches characterize each detector pixel, considering the detector in bulk. In this article, we propose a new microscopic learning-based physical models of RTSD based on limited data compared to what is dictated by the physical equations. Our learning models uses a physical charge transport considering trapping centers. Our models learn these material properties in an indirect manner from the measurable signals at the electrodes and/or free and/or trapped charges distributed in the RTSD for electron–hole charge pair injections in the material. Based on the amount of data used during training our physical model, our algorithm characterizes the detector for charge drifts, trapping, detrapping and recombination coefficients considering multiple trapping centers or as a single equivalent trapping center. The RTSD is segmented into voxels spatially, and in each voxel, the material properties are modeled as learnable parameters. Depending on the amount of data, our models can characterize the RTSD either completely or in an equivalent manner.

Room temperature ionizing radiation detectors using colloidal PbSe QDs

In this study, we demonstrate that colloidal PbSe quantum dots (QDs) can be a viable active material for room temperature semiconductor radiation detectors (RTSDs). QDs were synthesized with two different recipes and ligand exchanged with NH4SCN and 1-octanethiol when needed. When the QDs were fully dried, simple pellet architectures were manually pressed and I-V sweeps were performed to determine material resistivity. By varying QD diameters and ligand combinations the pressed pellet resistivity could be tuned between 104–1013Ω cm. When exposing devices to 133Ba radiation, full energy deposition peaks in pulse height spectra proved difficult to obtain. Sensitivity to the radiation could be ascertained once material resistivity reached ≥108Ω cm. Several devices demonstrated that resolution (peak full width half max over peak centroid) at 81 keV could be achieved with values of 4.75% and 5.98%. We found that performance was highly dependent on the contact point of a given superstructure. A comparison to other studies using colloidal QDs as an RTSD materials indicate that our results show similar performance. Further, our results are an improvement in performance compared to recent single crystalline RTSD materials such as CdSe.

KITE: High frame rate, high count rate pixelated electron counting ASIC for 4D STEM applications featuring high-Z sensor

KITE is a novel mixed-mode CMOS electron counting ASIC developed for the readout of pixelated semiconductor radiation detectors targeted to 4D STEM applications. The chip features a pixel pitch of 100 μm arranged in a 192 × 192 matrix and can be bump-bonded to both Si and high-Z sensor materials. The design of an extremely fast front-end electronics and the use of the instant retrigger mechanism allow for a non-paralyzable counting mode up to above 108 cts/s/pix, which corresponds to a 300 keV electron beam current of 14 pA/pix. The massive parallel readout in combination with two on-chip data compression techniques – 2 × 2 pixel digital binning and floating-point counter encoding – allows for frame rates higher than 100 kfps (this work), in principle extendable to almost 500 kfps with improved readout boards. We successfully characterized a first detector prototype featuring a 1500 μm-thick CdZnTe sensor with fluorescence X-rays from elemental targets and with 200 keV and 300 keV electrons in terms of energy response, threshold trimming accuracy, single event multiplicity distribution, spatial uniformity and temporal stability, count rate capability and imaging performances (MTF and DQE). Custom Monte Carlo simulations complemented when possible the experimental data for cross-validation purposes, generally with a very good matching. Finally, a proof-of-concept 4D STEM acquisition is presented and discussed.

Fiber laser system of 1550 nm femtosecond pulses with configurable properties for the two-photon excitation of transient currents in semiconductor detectors.

A fiber laser system emitting ultrashort femtosecond pulses at 1550 nm with configurable properties has been developed as an excitation source for the two-photon absorption transient current technique (TPA-TCT). The modules of the system are designed to provide the optical specifications required at the output for localized characterization of semiconductor radiation detectors: variation of pulse energy between 10 nJ and 10p J, variation of the pulse repetition rate from 8.2 MHz to single shot, and variation of pulse duration between 300 and 600 fs. The validity of the system as an excitation source in the TPA-TCT is demonstrated by measuring spatially resolved excited charge carriers in a silicon detector.