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The Low Gain Avalanche Detector (LGAD) technology is proposed for the ATLAS High Granularity Timing Detector (HGTD) and the CMS Endcap Timing Layer (ETL) towards the High-Luminosity Large Hadron Collider (HL-LHC), for which radiation hardness is one of the key requirements. In this paper we report results from the measurements on LGAD sensors designed by the University of Science and Technology of China (USTC) and fabricated by the Institute of Microelectronics of the Chinese Academy of Science (IME, CAS). These sensors have been irradiated with irradiation fluences of 8 × 1 0 14 , 1. 5 × 1 0 15 , 2. 5 × 1 0 15 and 6 × 1 0 15 cm−2 1 MeV neutron equivalent. Both un-irradiated and irradiated sensors were measured with a 90Sr-based beta scope at − 30 ∘ C to extract the collected charge and time resolution. The results show that sensors with carbon implantation can provide collected charge of more than 4 fC and time resolution better than 70 ps at appropriate bias voltage even for the equivalent fluence of 2. 5 × 1 0 15 cm−2. Both the collected charge and the time resolution meet the design specification of HGTD. [ABSTRACT FROM AUTHOR]

Organic photovoltaics (OPV) has been considered for a long time a promising emerging solar technology. Currently, however, market shares of OPV are practically non-existent. A detailed meta-analysis of the literature published until mid-2021 is presented, focusing on one of the remaining issues that need to be addressed to translate the recent remarkable progress, obtained in devices' performance at lab-scale level, into the requirements able to boost the manufacturing-scale production. Namely, the active layer's thickness is referred to, which, together with device efficiency and stability, represents one of the biggest challenges of this technological research field. Papers describing solar cells containing non-fullerene acceptor (NFA) binary and ternary blends, as well as NFA plus fullerene acceptor (FA) ternary blends are reviewed. The common ground of all analyzed devices is their high-thickness active layers, compatible with large-area deposition techniques. By defining a new figure of merit to discuss the OPV thickness (thickness tolerance, TT), it is found that this parameter is not affected by the chemical family's nature of the active blend components. On the other hand, the analysis suggests that there are promising strategies to improve the TT, which are discussed in the conclusion section., (© 2023 Wiley-VCH GmbH.)

A novel, multi-point contact high-purity germanium detector has been developed for applications in high-rate gamma environments. The planar detector was fabricated with seven point contacts, a high-voltage steering grid and bias electrode using amorphous germanium technology. We have characterized this detector and report herein on the depletion profile, leakage current, energy resolution, and charge-sharing behavior. [ABSTRACT FROM PUBLISHER]

An ultra-thin 3-D detector (U3DTHIN) with a 10-\mum-thick active region has been proposed to apply for microdosimetry in heavy ion therapy where the ion beam incidence is normal to the detector. The advantage of the detector is that the detector substrate below the silicon-on-insulator layer has been etched away. Extremely small columnar 3-D electrodes allow the detector to be fully depleted at very low biases with a minimum dead region due to their size. In this paper, a charge collection study of the U3DTHIN detector carried out using an ion beam-induced charge collection (IBICC) technique is presented. The IBICC study utilized a microbeam of 5.5 MeV He^2 + and 20 MeV^12C ions focused to approximately 1-\mum diameter. Full charge collection was observed from a bias as low as -10 V. A comparison of the detector response when irradiated from the front and rear side is also presented. [ABSTRACT FROM PUBLISHER]

A new computational model for charge transport based on parallelized random-walk drift-diffusion is proposed. This approach models the radiation-induced charge carriers as charge packets in a 3-D structure and the transport modeling are based on simple physical equations without any fitting parameter. This model has been dynamically coupled with a SPICE circuit simulator to take into account temporal variations of the electric fields in the charge collection process. Thus, the circuit electrical response modulates the charge collection efficiency. Three simulation cases have been explored and compared with TCAD simulations or radiation experiments in 65 nm technology to validate the accuracy of the proposed approach. These simulations demonstrate the capability of the proposed model to accurately estimate the soft error rate of complex structures, such as flip-flops over a large range of ionizing particle linear energy transfer. The proposed simulation methodology is also able to take into account charge-sharing phenomenon, and this point is highlighted by a specific investigation on the considered flip-flop. [ABSTRACT FROM PUBLISHER]

The single-event transient (SET) response of a third-generation bulk C-SiGe (\ npn + \ pnp) BiCMOS platform is investigated for the first time. Pulsed-laser, two-photon absorption experiments show that the pnp SiGe heterojunction bipolar transistor (SiGe HBT) exhibits a significant reduction in sensitive area as well as an improved transient response compared with the npn SiGe HBT. Ion-strike simulations on 3-D TCAD, C-SiGe HBT models agree with experimental findings, showing a reduction in overall transient duration and collected charge for the pnp SiGe HBT. These improvements in device-level SETs are attributed to the n-well isolation layer present in the vertical material stack of the pnp HBT. These results suggest that precision analog, RF/mm-wave, and high-speed digital applications utilizing unhardened, high-performance bulk pnp SiGe HBTs should benefit from an inherently improved SEE response. [ABSTRACT FROM PUBLISHER]

The design of photoanode with highly efficient light harvesting and charge collection properties is important in photoelectrochemical (PEC) cell performance for hydrogen production. Here, we report the hierarchical In 2 O 3 :Sn/TiO 2 /CdS heterojunction nanowire array photoanode (ITO/TiO 2 /CdS-nanowire array photoanode) as it provides a short travel distance for charge carrier and long light absorption pathway by scattering effect. In addition, optical properties and device performance of the ITO/TiO 2 /CdS-nanowire array photoanode were compared with the TiO 2 nanoparticle/CdS photoanode. The photocatalytic properties for water splitting were measured in the presence of sacrificial agent such as SO 3 2− and S 2− ions. Under illumination (AM 1.5G, 100 mW/cm 2 ), ITO/TiO 2 /CdS-nanowire array photoanode exhibits a photocurrent density of 8.36 mA/cm 2 at 0 V versus Ag/AgCl, which is four times higher than the TiO 2 nanoparticle/CdS photoanode. The maximum applied bias photon-to-current efficiency for the ITO/TiO 2 /CdS-nanowire array and the TiO 2 nanoparticle/CdS photoanode were 3.33% and 2.09%, respectively. The improved light harvesting and the charge collection properties due to the increased light absorption pathway and reduced electron travel distance by ITO nanowire lead to enhancement of PEC performance. [ABSTRACT FROM AUTHOR]

Abstract: The spectroscopic and charge collection performance of a BE2825 Broad Energy Germanium (BEGe) detector has been experimentally investigated. The efficiency and energy resolution of the detector have been measured as a function of energy and the noise contributions to the preamplifier signal have been determined. Collimated gamma-ray sources mounted on an automated 3-axis scanning table have been used to study the variation in preamplifier signal shape with gamma-ray interaction position in the detector, so that the position-dependent charge collection process could be characterised. A suite of experimental measurements have also been undertaken to investigate the performance of the detector as a function of bias voltage and we report on anomalous behaviour observed when the detector was operating close to the depletion voltage. [Copyright &y& Elsevier]

By using optical electric-field-induced second-harmonic generation (EFISHG) measurement, we studied multiple photovoltaic (PV) effects which exist in multi-layer devices consisting of multiple pentacene and C60 layers stacked together in various sequence. Results verified that the photovoltaic effects happen on every donor-acceptor (DA) interface and induce multiple electric fields inside the devices. Meanwhile, the light degradation in film thickness direction changes the intensity and the relaxation time of the established internal electric fields. For the multi-layer devices with more than one DA interface, the internal electric fields with opposite directions always co-exist, which leads to suppress the total photovoltaic effect. Finally, we showed that the interaction between different internal electric fields is inhibited by decreasing the charge accumulation inside the organic active layer and thus the total PV effect of the device can be enhanced. [ABSTRACT FROM AUTHOR]

In order to measure the energy of neutron fields, with energy ranging from 8 keV to 1 MeV, a new primary standard is being developed at the IRSN (Institute for Radioprotection and Nuclear Safety). This project, \mu-TPC (Micro Time Projection Chamber), carried out in collaboration with the LPSC (Laboratoire de Physique Subatomique et de Cosmologie), is based on the nuclear recoil detector principle. The instrument is presented with the associated method to measure the neutron energy. This article emphasizes the proton energy calibration procedure and energy measurements of a neutron field produced at 127 keV with the IRSN facility AMANDE. [ABSTRACT FROM PUBLISHER]

We investigate the impact of performance boosters using mechanical stress on the Single-Event Transient (SET) response of nanometer scaled Fully-Depleted Silicon-On-Insulator (SOI) devices. Laser SET measurements show that the active silicon layer thickness is the most important contributor to the SET response of highly scaled Ultra-Thin SOI (UTSOI) devices compared to the impact of strain. This is then demonstrated by dedicated TCAD calculations performed without taking into account any strain engineering technique. Finally, heavy ion-induced charge collection mechanisms are analyzed through the measurement of fast transients to get additional insights into the impact of short channel effects on the SET response of nanometer scaled SOI devices. [ABSTRACT FROM PUBLISHER]

Ion-induced, time-resolved charge-collection measurements for p-channel AlGaSb/InGaSb field-effect transistors are reported for a range of gate and drain bias conditions. The transient response reveals two distinct contributions: a faster initial response (< 1~ns) followed by a slower, > 10~ns, relaxation. The slower contribution depends sensitively on the applied gate bias, is suppressed when the gate is made more positive toward depletion, and is identified with an enhanced source-drain current in which more charge is collected than is deposited by the ion. A model consistent with the experimental measurements suggests that the dynamics of the enhancement processes are associated with the trapping and detrapping dynamics of electrons in the AlGaSb barrier materials. [ABSTRACT FROM PUBLISHER]