Materials Today Electronics最新文献

Ultra-high mobility speciality is a critical figure of merit for ultrapure materials and high-speed optoelectronic devices. However, unintentional doping-inducing various scattering frequently deteriorates mobility capacity. Therefore, how to elucidate the origin of mobility deterioration is still an open and technically challenging issue. Here we report that unintentional-doping silicon ion would be propagated into the indium phosphide (InP)’s epitaxial layer via analysis of time-of-flight and dynamic secondary ion mass spectrometry. The unintentional silicon ion in the InP wafer surface is responsible for the subsequent InGaAs epitaxial layer's mobility attenuation. The first-principles calculations and Boltzmann transport theory prove that polar optical phonon scattering (Fröhlich scattering) in non-doping InGaAs is the dominant scattering mechanism at high temperatures over 100 K. In contrast, the low-temperature scattering process is dominated by ionized impurities scattering. The unintentional silicon ion improves the Fröhlich scattering-dominated critical temperature. Our findings provide insight into the mobility degeneration originating from unintentional pollution and underlying scattering mechanisms, which lay a solid foundation for developing high-grade, super-speed, and low-power photoelectronic devices.

Solar-blind photodetectors (SBPDs) are core essential components for many critical applications such as precision guidance, fire warning, and space communications. Ultra-wide bandgap semiconductor β-Ga₂O₃ is considered to be an ideal material for the fabrication of SBPDs. However, synthetizing β-Ga₂O₃ with high quality factor while simultaneously in situ modulation of electronic and optoelectronic properties to enhance performance has been challenging. Here, pulsed laser deposition (PLD) technology is used to synthesize high-quality β-Ga₂O₃ thin films on a sapphire substrate. The oxygen vacancy engineered β-Ga₂O₃ films can achieve in situ precise control of their surface morphology, optical parameters, and optoelectronic properties by simply adjusting the oxygen pressure. Meanwhile, the optimal thickness of the β-Ga₂O₃ film for the developing high-performance SBPD is ∼221 nm, determined by fitting and analyzing the optical parameters measured by the ellipsometry. Subsequently, the influence of oxygen pressure on the performance of β-Ga₂O₃ SBPD is thoroughly explored, considering the optimization of electrode size and deposition time. When the oxygen pressure is set to 15 Pa, the β-Ga₂O₃-based SBPD achieves highly competitive responsivity (R) and detectivity (D*) at 250 nm, with values of 1080 A·W⁻¹ and 1.4 × 10¹⁶ cm·W⁻¹·Hz^1/2, respectively. Additionally, the noise component of the β-Ga₂O₃ SBPD is further studied to calibrated the traditional device performance results. This work introduces a simple and straightforward approach to in situ tuning of the optoelectronic properties of β-Ga₂O₃, which is important for advancing β-Ga₂O₃ film growth technology and fabricating high-performance photodetectors.

Ferroic domains and relevant topological defects, such as domain walls and vortices, have gained significant attention as functional units for potential advancements in nanoelectronics. Pb(Zr_xTi_1-x)O₃ (PZT) is a tetragonal ferroelectric material at room-temperature, exhibiting remarkable piezoelectricity and intricate domain structures. In this work, we explore the ferroelectric properties, photoelectric reactions, and efficient manipulation pathways of the unconventional superstructures in epitaxial (101)-oriented PZT thin films. Employing piezoresponse force microscopy (PFM) and conductive atomic force microscopy (cAFM), we unveil the three-dimensional polarization configurations of the superdomain structures inherently featuring conductive charged domain walls. Our findings reveal an increase in photoactivity at the head-side charged domain walls, attributed to the band-bending mechanism. Additionally, we discover the enhanced photoelectrochemical (PEC) performance in the superdomain structures compared to the (101)-oriented PZT films with conventional c/a domains. Furthermore, time-dependent pulse voltages are utilized to dynamically assess local currents and realize direct conductivity modulation by manipulating distinct polarization states. The elucidation of the photoelectrical mechanism and delineation of diverse pathways for intermediate state control underscore the potential of ferroelectric superdomains in constructing functional photoelectronic nanodevices.

Resistive-switching (RS) memory devices, or memristors, necessitate active materials of which electronic resistance is tunable by an external electric field. Metal halide perovskites (MHP) are representative RS materials wherein the electronic resistance is modulated by migration of intrinsic native or extrinsic impurity mobile ions. Since the first demonstration of MHP-based RS memory nearly a decade ago, MHPs have proven their great potential for energy-efficient nonvolatile memory devices. Dynamic transport of the mobile ions further allows MHPs to exhibit multistate resistance tunability at multiple timescale, which can be harnessed for neuromorphic memristors. Herein, we provide a comprehensive review on progress in RS memory devices with MHPs and their applications for neuromorphic memristors. We discuss how the electronic resistance of the MHPs is modulated by dynamic mobile ions, and focus on the ionic-electronic correlation that involves doping phenomena in MHPs on account of previous theoretical predictions and experimental verifications. Finally, we provide our perspective on major hurdles of MHPs for real-world applications of emerging nonvolatile memory and neuromorphic memristor technology.