Search

Soft robots have the advantage of adaptability and flexibility in various scenarios and tasks due to their inherent flexibility and mouldability, which makes them highly promising for real‐world applications. The development of electronic skin (E‐skin) perception systems is crucial for the advancement of soft robots. However, achieving both exteroceptive and proprioceptive capabilities in E‐skins, particularly in terms of decoupling and classifying sensing signals, remains a challenge. This study presents an E‐skin with mixed electronic and ionic conductivity that can simultaneously achieve exteroceptive and proprioceptive, based on the resistance response of conductive hydrogels. It is integrated with soft robots to enable state perception, with the sensed signals further decoded using the machine learning model of decision trees and random forest algorithms. The results demonstrate that the newly developed hydrogel sensing system can accurately predict attitude changes in soft robots when subjected to varying degrees of pressing, hot pressing, bending, twisting, and stretching. These findings that multifunctional hydrogels combine with machine learning to decode signals may serve as a basis for improving the sensing capabilities of intelligent soft robots in future advancements. [ABSTRACT FROM AUTHOR]

Two-dimensional (2D) semiconductors are considered one of the most promising channel materials in devices for the future development of integrated circuits with low power consumption and high integration. As the size of the device gradually decreases, a key challenge is to reduce the contact resistance of nanoscale devices. Doping is a crucial strategy to realize low contact resistances in 2D devices, but there is still lack of simple and compatible doping methods. Here, we report a simple and localized doping strategy that adopts an ultrathin lithium phosphorus oxynitride (LiPON) as the buffer layer of electrodes to reduce the contact resistance of MoS2 transistors. This ultrathin buffer layer induces strong n-doping in the electrode contact area, thereby achieving nearly Ohmic contact in the devices. The contact resistances of LiPON/Ti/Au electrodes for different channel carrier densities are all lower than those of Ti/Au electrodes because the Schottky barrier height (SBH) for the LiPON/Ti/Au electrodes is only 8% of the value for the Ti/Au electrodes. This work provides a simple and compatible strategy for the development of high-performance 2D devices and deepens the understanding of the important role of doping in 2D electrical contacts. [ABSTRACT FROM AUTHOR]

Transparent electronics is a burgeoning field with exciting potential for next‐generation "see‐through" devices. The creation of high‐performance fully transparent ultraviolet photodetectors (PDs) is essential for enabling wearable and portable applications. In this study, metal–semiconductor–metal (MSM) type Al‐doped ZnO (AZO)/GaN/AZO and indium tin oxide (ITO)/GaN/ITO‐transparent ultraviolet PDs, are initially designed, utilizing AZO‐ and ITO‐transparent conductive electrodes. In these investigations, it is revealed that AZO and ITO form Ohmic and Schottky contacts, respectively, with GaN. Subsequently, building on these findings, a fully transparent Schottky barrier photodiode (SBPD) is developed for ultraviolet photodetection using AZO/GaN/ITO. The SBPD displays a high responsivity (R) of 1.41 × 103 A W−1, a detectivity (D*) of 6.85 × 1014 Jones, and a photo‐to‐dark current ratio exceeding 1 × 104 at a − 5 V bias. Furthermore, the SBPD demonstrates an ultrahigh responsivity of 1.18 A W−1 at 0 V bias, indicating its potential as a self‐powered device under extreme conditions. In these results, the tremendous potential of the high‐performance and fully transparent GaN‐based SBPD is demonstrated for environmental monitoring, optical communication, military radar, and other fields. [ABSTRACT FROM AUTHOR]

Hybrid organic–inorganic metal halide perovskites are emerging materials in photovoltaics, whose bandgap is one of the most crucial parameters governing their light‐harvesting performance. This work presents the temperature and photocarrier density dependence of the bandgap in two phase‐stabilized perovskite thin films (MA0.3FA0.7PbI3 and MA0.3FA0.7Pb0.5Sn0.5I3) using photoluminescence and absorption spectroscopy. Contrasting bandgap shifts with temperature are observed between the two perovskites. Using X‐ray diffraction and in situ high‐pressure photoluminescence spectroscopy, it is shown that thermal expansion plays only a minor role in the large bandgap blueshift, which is attributed to the enhanced structural stability of the samples. The first‐principles calculations further demonstrate the significant impact of thermally induced lattice distortions on the bandgap widening. It is proposed that the anomalous trends are caused by the competition between static and dynamic distortions. Additionally, both the bandgap renormalization and band‐filling effects are directly observed for the first time in fluence‐dependent photoluminescence measurements and are employed to estimate the exciton effective mass. The results provide new insights into the basic understanding of thermal and charge‐accumulation effects on the band structure of hybrid perovskite thin films. [ABSTRACT FROM AUTHOR]

Dendrite growth behavior in a thin lithium phosphorus sulfide (LPSC) solid electrolyte has not been well revealed due to the lack of a suitable characterization method. This work introduces a unique yet simple method to monitor dendrite growth inside a pressurized all-solid-state cell in real time. Once a lithium metal dendrite penetrates through a thin LPSC layer and enters a LPSC-PTFE (polytetrafluoroethylene) indicator layer, it will react with PTFE and form a black-colored electron-conductive substance that traces the dendrite growth pathways, which can be in situ or ex situ observed using an optical microscope. It is shown that dendrites tend to grow through a very thin LPSC layer even at a very low current density, probably along the pre-existing chains of defects, revealing a potential challenge for practical application of all-solid-state lithium metal batteries. To address this challenge, we added an appropriate amount of LiF in LPSC electrolyte to increase its interface energy with lithium and effectively inhibit dendrite growth. Using the LPSC-LiF composite electrolyte, a Li‖Li symmetric cell can achieve 1800 h ultralong cycling life at a current density of 0.5 mA cm−2 and an all-solid-state Li‖LPSC-LiF‖LiCoO2 full cell can operate over 200 cycles without short-circuiting, showing great promise for its application in future all-solid-state lithium metal batteries. [ABSTRACT FROM AUTHOR]