Electron sources play as important component in a wide range of applications. Here, the authors demonstrate efficient, regenerative, and low-cost electron sources based on solution-processed halide perovskite thin films with quantum efficiency up to 2.2% and a lifetime of more than 25 h.
Electronic and photonic technologies have revolutionised our world and fortified many areas of our modern life. Fundamental and applied research spanning from atoms to devices leading to new technology development, including quantum, atomic, spintronic, optics, nuclear, plasma, superconductors, and low-dimensional materials based devices, is crucial to ensure continuous solutions to existing and future global challenges.
Achieving bright and efficient blue emission in metal halide perovskite light-emitting diodes has proven to be challenging. Here, the authors demonstrate high EQE and spectrally stable blue light-emitting diodes based on mixed halide perovskites, with emission from 490 to 451 nm by using a vapour-assisted crystallization technique.
Single-layered organic photovoltaics with double cascading charge transport pathways: 18% efficiencies
Efficiency of organic solar cells is determined by the physical properties of donors and acceptors in bulk heterojunction film. The authors optimise quaternary blends to realize a double cascading energy level alignment enabling efficient carrier dissociation and transport, achieving 18% efficiency.
Fabrication of efficient large-area perovskite light emitting diodes catering towards mass-production is hampered by the difficulty in getting homogenous uniform films and the high cost. Here, the authors demonstrate sol-gel engineering of low-temperature blade-coated perovskite films which can overcome these limitations.
Perovskite nanocrystals are promising emitters but suffer from environmental instabilities. Here, Park et al. introduce aromatic nonpolar organogels as a soft passivating matrix of perovskites, demonstrating highly efficient and environmentally stable luminescent nanocomposites.
2D-3D integration of hexagonal boron nitride and a high-κ dielectric for ultrafast graphene-based electro-absorption modulators
Here, three-dimensional hafnium oxide and two-dimensional hexagonal boron nitride are integrated in the insulating section of double-layer graphene optical modulators, leading to a maximum bandwidth of 39 GHz and enhanced modulation efficiency.
Robust metal ion-chelated polymer interfacial layer for ultraflexible non-fullerene organic solar cells
Simultaneously achieving high efficiency and mechanical robustness is challenging for ultraflexible organic solar cells. Here, Qin et al. present a robust interlayer of Zinc-chelated polyethylenimine (PEI-Zn) to facilitate the demonstration of efficient and mechanically robust ultraflexible solar cells.
Here, a strong nonlinearity of the gate-induced tunnel junction in bilayer graphene is used for efficient terahertz detection. The improved signal-to-noise ratio, as compared to conventional detectors, offers the application of steep-switching transistors in terahertz technology.
Solid-state nanopores can serve as single molecule sensors for DNA sequencing, but the current designs suffer from fast DNA translocation so low detectivity. Wang et al. slow down and control the translocation speed by 5 orders of magnitude using a leakage field generated at the nanopore tip.
Photo thermal effect graphene detector featuring 105 Gbit s−1 NRZ and 120 Gbit s−1 PAM4 direct detection
The fast carrier dynamics and ultra-broadband optical properties of graphene make it suitable for optical communications. Here, the authors demonstrate a photo-thermo-electric graphene photodetector integrated on a Si waveguide featuring 105 Gbit s−1 non-return to zero and 120 Gbit s−1 4-level pulse amplitude modulation direct detection.
Here, the authors perform a benchmark study of field-effect transistors (FETs) based on 2D transition metal dichalcogenides, i.e., 230 MoS2 and 160 WS2 FETs, and track device-to-device variations to gauge the technological viability in future integrated circuits.
Roll-to-roll gravure-printed flexible perovskite solar cells using eco-friendly antisolvent bathing with wide processing window
Driven by recent improvement in efficiency and stability of perovskite solar cells, the next step toward commercialisation is upscaling. Here, the authors demonstrate pilot-scale fully roll-to-roll manufacturing of flexible perovskite solar cells through gravure-printing and antisolvent bathing.
Two-dimensional ferroelectric channel transistors integrating ultra-fast memory and neural computing
Ferroelectric devices with dielectric layers to modulate channel conductance have limited endurance and miniaturization. Here, the authors demonstrate a 2D ferroelectric channel transistor that integrates memory and computation capabilities, that will support the development of memory and computing fusion systems.
Magnons - collective excitations of electron spins - promise compact and fast electronics. However, the generation of short wave magnons is still quite challenging. Here, the authors demonstrate that by introducing a ferromagnetic layer, conventional coplanar waveguides can be used to efficiently generate such magnons.
Real-time monitoring human motions normally demands connecting a large number of sensors in a complicated network. To make it simpler, Kim et al. decode the motion of fingers using a flexible sensor attached on wrist that measures skin deformation with the help of a deep-learning architecture.
Designing efficient system for digital connectivity preserving information security remains a challenge. Here, the authors present hardware-intrinsic security solutions based on physical unclonable functions incorporating an inkjet-printed core circuit as an intrinsic source of entropy, integrated into a silicon-based CMOS system environment.
Here, the authors report ultrasensitive negative capacitance phototransistors based on MoS2 regulated by a layer of ferroelectric hafnium zirconium oxide film to demonstrate a hysteresis-free ultra-steep subthreshold slope of 17.64 mV/dec and specific detectivity of 4.75 × 1014 cm Hz1/2 W−1 at room temperature.
The lack of scalable, high-quality insulators is a major problem hindering the progress on electronic devices built from 2D materials. Here, the authors review the current state-of-the-art and the future prospects of suitable insulators for 2D technologies.
On-chip deterministic operation of quantum dots in dual-mode waveguides for a plug-and-play single-photon source
Resonantly-excited quantum-dot-based single photon sources feature very high purity, but also limited efficiency due to the need to suppress the residual pump. Here, the authors demonstrate a workaround, performing optical pumping and signal collection in two orthogonal modes inside a nanophotonic circuit.
Most demonstrations of optical neural networks for computing have been so far limited to real-valued frameworks. Here, the authors implement complex-valued operations in an optical neural chip that integrates input preparation, weight multiplication and output generation within a single device.
Integration of III-V semiconductor microlasers into modern Si or Si3N4 based photonic integrated circuits remains a challenge. Here, the authors demonstrate a perovskite vortex microlaser with highly directional outputs and well-controlled topological charges that is highly compatible with most materials.