Materials for devices

  • Article |

    Knowledge of band structure aids in understanding charge transport behaviour, yet it has proved impossible to measure the conduction (LUMO) band of organic semiconductors, in particular due to sample degradation by the electron beam. To address this, the authors developed and used AR-LEIPS to reveal the LUMO band dispersion of pentacene.

    • Haruki Sato
    • , Syed A. Abd. Rahman
    •  & Hiroyuki Yoshida
  • Article |

    Hafnium dioxide is of technological interest as it is compatible with silicon; however, previous work indicates that a nanometre grain size is required to generate ferroelectricity. Here ferroelectric Y-doped HfO2 thin films with high crystallinity are grown with large crystal grain sizes, indicating that ferroelectricity is intrinsic.

    • Yu Yun
    • , Pratyush Buragohain
    •  & Xiaoshan Xu
  • Article |

    Electrostatic capacitors can enable ultrafast energy storage and release, but advances in energy density and efficiency need to be made. Here, by doping equimolar Zr, Hf and Sn into Bi4Ti3O12 thin films, a high-entropy stabilized Bi2Ti2O7 pyrochlore phase forms with an energy density of 182 J cm−3 and 78% efficiency.

    • Bingbing Yang
    • , Yang Zhang
    •  & Yuan-Hua Lin
  • Article |

    Thin films of BaTiO3 do not possess the same small switching fields and energies as the single-crystal form, hindering applications. Here, thin films are synthesized that enable switching for voltages <100 mV and fields <10 kV cm–1, and a pathway to subnanosecond switching is presented.

    • Y. Jiang
    • , E. Parsonnet
    •  & L. W. Martin
  • Article |

    Fabrication of semiconductor heterojunctions typically involves a complex process and often leads to bioincompatibility. Here, the authors propose a porous heterojunction in p-type silicon via simple stain etching at ambient conditions, and apply it in optically induced biomodulation.

    • Aleksander Prominski
    • , Jiuyun Shi
    •  & Menahem Y. Rotenberg
  • Article |

    Semipermeable polymeric anion exchange membranes are essential for separation, filtration and energy conversion technologies such as fuel cells. Quasi-elastic neutron scattering is now used to disentangle water, polymer relaxation and OH diffusional dynamics in a commercially available membrane.

    • Fabrizia Foglia
    • , Quentin Berrod
    •  & Paul F. McMillan
  • Review Article |

    Thermoelectric materials can generate energy from a heat differential. This Review provides an overview of mid- to high-temperature thermoelectrics, their application in modules, and the issues that need to be addressed to enable commercial implementation of state-of-the-art materials.

    • Qingyu Yan
    •  & Mercouri G. Kanatzidis
  • Review Article |

    This Review provides an outlook on current understanding of the role of strain on the performance and stability of perovskite solar cells, as well as on tools to characterize strain in halide perovskite films and on strain management strategies.

    • Dongtao Liu
    • , Deying Luo
    •  & Wei Zhang
  • Article |

    A two-dimensional hole gas with high carrier density is confined at the interface between a solution-processed, single-crystalline organic semiconducting film and the electric double layer formed by an ion gel on top of the film.

    • Naotaka Kasuya
    • , Junto Tsurumi
    •  & Jun Takeya
  • Article |

    A functional interfacial material has been developed for soft integration of bioelectronic devices with biological tissues. This has been applied in battery-free optoelectronic systems for deep-brain optogenetics and subdermal phototherapy as well as wireless millimetre-scale pacemakers and flexible multielectrode epicardial arrays.

    • Quansan Yang
    • , Tong Wei
    •  & John A. Rogers
  • Review Article |

    Metal-halide and oxide perovskites are a rich playground for fundamental studies and applications. This Review focuses on the opportunities opened by reducing the dimensionality of these materials to two-dimensional monolayers.

    • Antonio Gaetano Ricciardulli
    • , Sheng Yang
    •  & Michael Saliba
  • Article |

    Stacked elastomeric arrays containing plasmonic nanoparticles show efficient chiral responses that can be fully controlled by mechanical compression and stack rotation. These simple layered materials may be useful modulators for photonic applications.

    • Patrick T. Probst
    • , Martin Mayer
    •  & Andreas Fery
  • Article |

    Adducts of dimethyl sulfoxide and hydrobromic acid demonstrate efficient p-doping of various organic semiconductors and compatibility with other counterions used to improve stability and other performance parameters of organic-based optoelectronic devices.

    • Nobuya Sakai
    • , Ross Warren
    •  & Henry J. Snaith
  • Article |

    Porous materials can absorb energy by water infiltration, but studies at industrially relevant high-rate intrusions are rare. Here, high-rate experiments are performed on ZIFs showing high energy storage capacity, while molecular simulations allow design rules to be formulated for absorption materials.

    • Yueting Sun
    • , Sven M. J. Rogge
    •  & Jin-Chong Tan
  • Article |

    A general method for the synthesis of high-purity crystals of metastable 1T′-phase transition metal dichalcogenides is reported, providing a source of phase-engineered materials that can be used to systematically explore their intrinsic properties.

    • Zhuangchai Lai
    • , Qiyuan He
    •  & Hua Zhang
  • Article |

    Conductors made of a mixture of liquid and solid domains of Ga–In alloy can be stretched over 1,000%, keeping almost constant conductivity, and used to connect commercial electronic components and realize stretchable multilayer printed circuit boards.

    • Shanliangzi Liu
    • , Dylan S. Shah
    •  & Rebecca Kramer-Bottiglio
  • Article |

    Upon light stimulation, two jointed liquid crystalline network oscillators affect the movement of each other, achieving synchronized in-phase and anti-phase oscillations that can be explored to generate soft actuators with collective responses.

    • Ghislaine Vantomme
    • , Lars C. M. Elands
    •  & Dirk J. Broer
  • Perspective |

    Thermoelectric materials can generate electricity from waste heat but can also use electricity for cooling. This Perspective discusses coefficients of performance for these systems and the state-of-the-art for materials, and suggests strategies for the discovery of improved thermoelectric materials.

    • Jun Mao
    • , Gang Chen
    •  & Zhifeng Ren
  • Article |

    Phosphonated polymers have been proposed as anhydrous proton conductors for fuel cells but anhydride formation of phosphonic acid functional groups lowers conductivity. A synergistically integrated phosphonated poly(pentafluorostyrene) is shown to maintain high protonic conductivity above 200 °C.

    • Vladimir Atanasov
    • , Albert S. Lee
    •  & Yu Seung Kim
  • Perspective |

    Although low-temperature water electrolysers are crucial for decarbonizing the industrial sector, substantial improvements in performance and deployment rates are needed. Recent developments in devices with modified architectures and designs, and practical challenges hampering large-scale deployment are discussed.

    • Marie Francine Lagadec
    •  & Alexis Grimaud
  • Article |

    A graphene nanocomposite hydrogel showing anisotropic swelling is used to realize an electrically conducting and removable bioadhesive that improves the mechanical and electrical integration of bioelectronics devices with wet dynamic tissues.

    • Jue Deng
    • , Hyunwoo Yuk
    •  & Xuanhe Zhao
  • Article |

    Protein-based materials for soft robotics that self-heal within a second while maintaining the high strength of the damaged area are reported.

    • Abdon Pena-Francesch
    • , Huihun Jung
    •  & Metin Sitti
  • Perspective |

    Semimetal photodetectors provide high-speed and broadband operation but suffer from serious drawbacks such as high dark currents. This Perspective discusses the opportunities offered by topological effects to overcome these issues and improve their performance.

    • Jing Liu
    • , Fengnian Xia
    •  & Dong Sun
  • Letter |

    A cell culture interfacing an organic neuromorphic device in a microfluidic system reversibly modifies the device synaptic weight through chemical reactions mediated by the release of dopamine, a neurotransmitter used in biological synapses.

    • Scott T. Keene
    • , Claudia Lubrano
    •  & Francesca Santoro
  • Article |

    The energy density of dielectric ceramic capacitors is limited by low breakdown fields. Here, by considering the anisotropy of electrostriction in perovskites, it is shown that <111>-textured Na0.5Bi0.5TiO3–Sr0.7Bi0.2TiO3 ceramics can sustain higher electrical fields and achieve an energy density of 21.5 J cm−3.

    • Jinglei Li
    • , Zhonghui Shen
    •  & Fei Li