Lithium indium phosphorus selenide, 6 LiInP 2 Se 6 (LIPSe), has been proposed as a novel semiconductor detector for neutron scattering science applications. Compared with 3 He gas and scintillation detectors currently in use at neutron scattering facilities, semiconductors, such as LIPSe, offer excellent timing and spatial resolution with acceptable efficiency. A known drawback of semiconductor detectors is the low tolerance of heavy charged particle radiation such as the products emitted by the 6 Li( n , T) 4 He reaction used for the detection of neutrons. It is therefore necessary to study whether or not LIPSe is capable of withstanding the level of neutron fluence it may be exposed to throughout operational service as part of a thorough investigation of its suitability for use in instrumentation at modern beam lines. An analysis of radiation damage to LIPSe was conducted using grazing incidence X‐ray diffraction, UV–vis spectroscopy, Raman spectroscopy, and direct measurements of alpha radiation response. Results suggest that thin samples retain operability as a neutron detector at up to 10 15 n/cm 2 s, though some sources of systematic error may cause alpha response spectra to be degraded beyond what might be expected in practical applications.
The impact of shallow acceptor doping on p‐coronene (L2)‐based organic solar cells was investigated using SCAPS‐1D simulations with DFT‐derived parameters. Acceptor density ( N a ) was varied from 1 × 10 12 to 1 × 10 23 cm −3 , and current density–voltage characteristics were analyzed. The photovoltaic parameters reveal three distinct doping regimes. In the low‐doping regime ( N a ≤ 10 16 cm −3 ), device performance remains nearly unchanged, with J sc ≈ 19.34 mA cm −2 , V oc ≈ 0.787 V, FF ≈ 54%, and η ≈ 8.22%. Above 10 17 cm −3 , V oc and FF increase monotonically while J sc stays above 15 mA cm −2 up to 10 22 cm −3 , leading to continuous efficiency improvement. At the highest doping (10 23 cm −3 ), J sc drops to ~1.49 mA cm −2 , but gains in V oc (1.07 V) and FF (80.2%) yield a maximum efficiency of 12.83%. For N a ≥ 10 17 cm −3 , a power‐law dependence ( η ∝ N 0.37 ) is observed. The optimum doping concentration is 10 22 cm −3 , achieving η = 12.02%, J sc = 14.96 mA cm −2 , V oc = 1.01 V, and FF = 79.58%. These results demonstrate that controlled shallow acceptor doping is an effective strategy to simultaneously enhance V oc and FF while maintaining high photocurrent, providing guidelines for optimizing high‐performance coronene‐based organic solar cells.
This work investigates the effect of scaling on the electrostatic behavior of cross‐shape reconfigurable field‐effect transistors (RFETs) using three‐dimensional technology computer‐aided design simulations. The emerging device concept consists of multiple nanowires in a junction of a common channel, where multiple gates are aligned on the silicon and silicide junction interface, enabling polarity switching and signal routing within a compact layout. Although such a geometry can be utilized for new directions in neuromorphic or analog computation, it significantly increases the electrostatic interactions. The focus of the work is to understand the impact of the gate‐to‐gate distance and nanowire width on the on‐state current. The energy barrier in the ungated common‐channel region was found to be the limiting factor, as excessive fringing field coupling at short gate‐to‐gate distances causes electrostatic crowding and barrier sharpening, thereby restricting carrier transport. To overcome the electrostatic limitation of the cross‐shape RFET, a three‐dimensional U‐shape RFET was proposed. Due to its gate‐all‐around coverage of the metal–semiconductor junctions, electrostatic control was found to be stronger. U‐shape geometry achieves a high on‐state current with a minimal sensitivity to gate‐to‐gate distance variations. This work derives practical design guidelines for 3D RFET architectures, aiming to balance device compactness and electrostatic efficiency.
This article proposes a novel high electron mobility transistor (HEMT) device with a triple‐barrier‐layer (TBL‐HEMT) structure of AlGaN. The conventional 15 nm single AlGaN barrier is divided into three sublayers with Al compositions of 0.25, 0.20, and 0.15 from top to bottom. In order to enhance radio frequency (RF) performance, a 1 μm linearly graded AlGaN underlying layer is employed to efficiently suppress short channel effect during device scaling. Three types of stacked passivation films including HfO 2 /SiO 2 , Al 2 O 3 /SiO 2 , and SiO 2 /SiO 2 are analyzed, and a 100 nm air gap near the gate helps cut parasitic gate capacitance greatly. The optimized SiO 2 /SiO 2 (air = 100 nm) scheme delivers the highest cutoff frequency ( f T ) of 114 GHz. The device under consideration in this article demonstrates a high cutoff frequency, excellent direct current performance, and a very high RF quality factor. These characteristics offer substantial reference value for future applications in the domain of RF electronics.
This paper presents a finite element analysis study on the impact of material selection and sensor geometry on the performance metrics of a microelectromechanical systems piezoresistive readout‐based pressure sensor for biomedical applications. The pressure sensor dimensions are designed for housing in a typical 5Fr catheter utilized for in vivo biomedical applications. In this work, focus is on devising a rational selection of piezoresistor material and sensor geometry for maximizing performance metrics of the sensor. For investigation, we have considered three generations of piezoresistive materials which exhibit a wide range of gauge factors. Subsequently, the study explores different sensor mechanical diaphragm geometries, focusing on stress distributions, displacements, and variations in resistance governing sensitivity and structural nonlinearity. Simulation results show that for constant resonant frequency and fixed piezoresistors, among the sensor geometries, circular geometry of sensor platform depicts the highest electrical sensitivity. Among piezoresistor materials, gold has the lowest sensitivity (1.229 × 10 −4 ), confirming its weak piezoresistive nature. P‐type silicon demonstrates moderate sensitivity, reaching up to (6.779 × 10 −4 ). On the other hand, response of graphene nanoplate SU‐8 is the highest (9.501 × 10 −4 ). Results show that nonlinearity errors for square, octagonal, and circular geometries are −0.637%, −0.431%, and −0.420%, respectively, within a pressure range of 0–100 mmHg.
