Yun Li

Nanjing University | NJU · School of Electronic Science & Engineering

D organic materials with in-plane van der Waals forces among molecules have unique characteristics that ensure a brilliant future for multifunctional applications. Soluble organic semiconductors can be used to achieve low-cost and high-throughput manufacturing of electronic devices. However, achieving solution-processed 2D single-crystalline semico...

Ferroelectric organic field-effect transistors (Fe-OFETs) have attracted intensive attention because of their promising potentials in non-volatile memory devices. The quick switching between binary states is a significant fundamental feature in evaluating Fe-OFET memories. Here, we employ 2D molecular crystals via a solution-based process as the co...

A general understanding of the nature of the charge motions at the organic/dielectric interface requires an accurate examination on the influence from the Coulomb interactions among carriers. However, difficulties on this substantial issue are due to complicated interpretation and extraction of the intrinsic electrical parameters for the organic fi...

Phototunable synaptic elements are beginning to emerge for the sustainable development of advanced neuromorphic computing technology in the post‐Moore era. However, the phototunable organic synaptic devices still hardly exhibit superior overall performances. Here, an optically modulated organic planar‐diode‐based artificial synapse is demonstrated...

Dynamic disorders, which possess a finite charge delocalization, play a critical role in the charge transport properties of high-mobility molecular organic semiconductors. The use of two-dimensional (2D) charge transport in crystalline organic semiconductors can effectively facilitate reducing the sensitivity of charge carriers to thermal energetic...

In biological visual systems, retina with bidirectional photoresponse can adapt to variable environments and modulate their photosensitivity dependent on illumination conditions in an energy‐efficient way. However, to emulate the visual functionality, current systems still require a sustained power supply and manipulate the electrical stimulation m...

Molecular diodes are of considerable interest for the increasing technical demands of device miniaturization. However, the molecular diode performance remains contact‐limited, which represents a major challenge for the advancement of rectification ratio and conductance. Here, it is demonstrated that high‐quality ultrathin organic semiconductors can...

Organic field‐effect transistors switched by insulated gates are the most essential building blocks, while usually plagued with degraded gate control arising from complicated dielectric engineering. Subsequently, the resulting large supply voltage and power consumption remain an essential issue for portable electronics driven by a single battery of...

Hardware implementations tailored to requirements in reservoir computing would facilitate lightweight and powerful temporal processing. Capacitive reservoirs would boost power efficiency due to their ultralow static power consumption but haven't been experimentally exploited yet. Here we report an oxide‐based memcapacitive synapse (OMC) based on Zr...

The human visual system (HVS) has the advantages of a low power consumption and high efficiency because of the synchronous perception and early preprocessing of external image information in the retina, as well as parallel in-memory computing within the visual cortex. Realizing the biofunction simulation of the retina and visual cortex in a single...

The rapid development of digital technology results in a tremendous increase in computational tasks that impose stringent performance requirements on next‐generation computing. Biological neurons with fault tolerance and logic functions exhibit powerful computing capacity when facing complex real‐world problems, which strikes the inspiration for th...

The growing computational demand in artificial intelligence calls for hardware solutions that are capable of in situ machine learning, where both training and inference are performed by edge computation. This not only requires extremely energy-efficient architecture (such as in-memory computing) but also memory hardware with tunable properties to s...

The growing computational demand in artificial intelligence (AI) calls for hardware solutions that are capable of in-situ machine learning, where both training and inference are performed by edge computation. This not only requires extremely energy efficient architecture (such as in-memory computing, IMC) but also memory hardware with tunable prope...

Two-dimensional organic semiconductors (2D OSCs) are important functional materials for the fabrication of next-generation high-performance devices with intrinsic electrical properties. However, the development of large-area n-type 2D OSCs with improved device performance and thermal stability is still a challenge due to the poor understanding of t...

Bioinspired organic sensors with excellent flexibility, biocompatibility, sensing performance, and self‐adaptability have attracted considerable attention due to their fundamental role in next‐generation intelligent sensory systems with simultaneous sensing and processing functions, such as advanced robots, disease diagnosis, Internet of Things, hu...

We report a nano-infrared (IR) imaging study of trilayer graphene (TLG) with both ABA (Bernal) and ABC (rhombohedral) stacking orders using the scattering-type scanning near-field optical microscope (s-SNOM). With s-SNOM operating in the mid-IR region, we mapped in real space the surface plasmon polaritons (SPPs) of ABA-TLG and ABC-TLG, which are t...

Organic field-effect transistors (OFETs) are of interest in unconventional form of electronics. However, high-performance OFETs are currently contact-limited, which represent a major challenge toward operation in the gigahertz regime. Here, we realize ultralow total contact resistance (Rc) down to 14.0 Ω ∙ cm in C10-DNTT OFETs by using transferred...

Molecular diodes are of considerable interest for the increasing technical demands of device miniaturization. However, the molecular diode performance remains contact-limited, which represents a major challenge for advancement of rectification ratio toward commercial availability. Here, we demonstrate that high-quality ultrathin organic semiconduct...

Herein, we demonstrate a highly-sensitive, flexible, and self-powered UV photodetector based on perovskites Cs <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> Cu <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> I <sub xmlns:mml="http://www.w...

We report an infrared (IR) imaging study of trilayer graphene (TLG) with both ABA (Bernal) and ABC (rhombohedral) stacking orders using the scattering-type scanning near-field optical microscope (SSNOM). With the SSNOM operating in the mid-IR region, we map in real space the surface plasmon polaritons of ABA TLG and ABC TLG, which are tunable with...

The increasing demands of multifunctional organic electronics require advanced organic semiconducting materials to be developed and significant improvements to be made to device performance. Thus, it is necessary to gain an in-depth understanding of the film growth process, electronic states, and dynamic structure-property relationship under realis...

The retina, the most crucial unit of the human visual perception system, combines sensing with wavelength selectivity and signal preprocessing. Incorporating energy conversion into these superior neurobiological features to generate core visual signals directly from incoming light under various conditions is essential for artificial optoelectronic...

Associative learning is a critical learning principle uniting discrete ideas and percepts to improve individuals’ adaptability. However, enabling high tunability of the association processes as in biological counterparts and thus integration of multiple signals from the environment, ideally in a single device, is challenging. Here, we fabricate an...

Optoelectronic synapses have attracted considerable attention because of their promising potential in artificial visual perception systems for neuromorphic computing. Despite remarkable progress in mimicking synaptic functions, reduction of energy consumption of artificial synapses is still a substantial obstacle that is required to be overcome to...

Electron-phonon interactions are fundamentally important physical processes responsible for many key discoveries in condensed matter physics and material sciences. Herein, by exploiting the scattering-type scanning near-field optical microscope (s-SNOM) excited with a femtosecond infrared (IR) laser, we explored the strong coupling between IR phono...

Nonvolatile memories (NVMs) using ferroelectric materials have attracted tremendous attention as a prerequisite for a large variety of organic electronic devices. While, the high on/off ratio should be taken increasing consideration especially for high-density integrated circuits for high data accuracy that approves large computing dynamic range an...

Fabricating 2D organic crystalline semiconductors (2DOCSs) in a patterned structure is an essential prerequisite for application toward large‐scale and high‐throughput manufacturing integrated devices. However, the deposition of 2DOCS arrays with structural perfection and thickness control through suitable solution‐based techniques remains challeng...

Carrier mobility extraction is easily influenced by the contact resistance, especially in transistors with high carrier mobility and short channel length, which would obscure the investigation into the charge transport in the organic field-effect transistors (OFETs). Here, we perfunctorily observe a hopping transport (∂μ/∂T > 0) and temperature-ind...

Correction for ‘Solution-processed organic single-crystalline semiconductors with a fence-like shape via ultrasound concussion’ by Bowen Zhang et al. , J. Mater. Chem. C , 2020, 8 , 2589–2593, DOI: 10.1039/C9TC06635G.

Charge carriers (electrons and holes) transport in between the source and drain electrodes in an organic transistor, which is the building block of organic circuits. In article number 1904508, Yong Xu, Huabin Sun, Jing Wan, Yufeng Guo, Yong‐Young Noh, and co‐workers describe three speedometers that indicate completely different carrier velocities,...

Despite the great efforts to unveil the charge carrier behavior at the semiconductor/dielectric interface of organic field-effect transistors, an examination of the interfacial carrier distribution and the correlation with the charge transport in molecular crystalline semiconductors remains fundamental for understanding the nature of the microscopi...

Organic UV photodetectors using a transistor architecture can yield higher photoresponsivity than diode‐based devices because of the presence of a gate electrode. However, a long‐term issue of these phototransistor devices is the slow response speed, which hinders their practical applications. Here, organic UV phototransistors are constructed using...

Despite the increasing understanding of charge transport in organic field-effect transistors (OFETs), charge injection from source/drain electrodes into organic semiconductors remains crucial for improving device performance and lowering power consumption. The analysis of contact resistance is generally carried out without clearly distinguishing th...

At present, the electrical performance of organic field-effect transistors (OFETs) has reached the level of commercial amorphous silicon. OFETs show considerable application potential in artificial intelligence, deep learning algorithms, and artificial skin sensors. The devices which can operate with high performance and low power consumption are n...

Well-aligned organic single-crystalline semiconductors are essential for practical applications in electronic devices. Here, we demonstrated dioctylbenzothienobenzothiophene (C8-BTBT) single crystals via ultrasound-assisted solution-processed method. Organic crystalline semiconductors with fence-like shape were achieved, where rod-like crystals wer...

Organic field-effect transistors (OFETs) have been the hotspot in information science for many years as the most fundamental building blocks for state-of-the-art organic electronics. During the field-effect modulation of the semiconducting channel, the gate dielectric always has a significant influence on the charge transport behaviours. Hence, und...

Polymeric materials are emerging as an important component for organic electronics due to their combined features of soft materials and organic semiconductor/conductor. Different from solid-state bulk materials, polymers are synthesized and modulated with a facile method, with their controllable properties. Therefore, polymers have been recently us...

Unreliable mobility values, and particularly greatly overestimated values and severely distorted temperature dependences, have recently hampered the development of the organic transistor field. Given that organic field‐effect transistors (OFETs) have been routinely used to evaluate mobility, precise parameter extraction using the electrical propert...

The mechanism of self-assembling process of inorganic nanoparticle is still an open question due to the various and non-additive interactions between NPs. Kotov and co-workers have reported that the semiconductor NPs can be self-assembled by external activation such as irradiation. In this paper, the twisted CdTe nanoribbons were successfully assem...

Ferroelectric organic field-effect transistors (Fe-OFETs) have attracted considerable attention because of their promising potential for memory applications, while a critical issue is the large energy consumption as mainly caused by a high operating voltage and slow data switching. Here, we employ ultrathin ferroelectric polymer and semiconducting...

Two-dimensional (2D) organic crystalline films with thickness of several molecular layers have unique characteristics that ensure a brilliant prospect for electronic applications. However, achieving solution-prepared n-type 2D organic single-crystalline semiconductor films remains to be a challenge. In this study, a “metal-wire-gap” process with ad...

Electronic skin, a kind of flexible electronic device and system inspired by human skin, has emerged as a promising candidate for wearable personal healthcare applications. Wearable electronic devices with skin-like confluence properties will provide platforms for continuous and real-time monitoring of human physiological signals such as tissue pre...

The newly emerging field in organic electronics is to control the molecule–substrate interface properties at a two-dimensional (2D) limit via interfacial interactions, which paves the way for driving the molecular assembly for highly ordered 2D molecular crystalline films with precise molecular layers and large-area uniformity. Here, by exploiting...

Soluble organic semiconductors have been widely researched for a wide range of application scenarios, such as organic field-effect transistors (OFETs), organic light-emitting diodes and solar cells. Due to their unique characteristics and great potentials as a platform for exploiting charge transport, two-dimensional (2D) organic crystals are emerg...

Based on intensive research, organic field‐effect transistors (OFETs) will likely remain at the zenith in information science for many years due to their numerous potential applications in portable and smart electronic devices. Elucidating the intrinsic charge‐transport behavior and realizing functional OFETs with superior device characteristics ha...

A chiral metastructure composed of spatially separated double semi-periodic helices is proposed and investigated theoretically and experimentally in this Letter. Chirality-dependent electromagnetically induced transparency (EIT) and a slow light effect in the microwave region are observed from a numerical parameter study, while experimental results...

The polymer poly(vinylidene fluoride-co-trifluoroethylene) (P(VDF–TrFE)) is highly desirable for piezoelectric and ferroelectric functional applications owing to its considerable electromechanical activity and reliable electrical polarization. However, a clear understanding of the effect of the thermal annealing on the electromechanical behavior an...

A chiral metastructure composed of spatially separated double semi-periodic helices is proposed and investigated theoretically and experimentally in this Letter. Chirality-dependent electromagnetically induced transparency (EIT) and a slow light effect in the microwave region are observed from a numerical parameter study, while experimental results...

We present an effective surface-enhancement Raman scattering(SERS) substrate enabled by depositing metallic film on a liquid surface at room temperature. Thermal evaporation is used to deposit Au atoms on silicone oil surface and then form quasi-continuous films. Due to the isotropic characteristics of the liquid surface, this film consists of subs...

Organic field-effect transistorsd are the most fundamental device unit in organic electronics. Interface engineering on the semiconductor/dielectric interface is an effective approach for improving device performance, particularly for enhancing charge transport at conducting channels. Here, we report flat-lying molecular monolayers that exhibit goo...

For the first time, H2O2 was used in CdS thin films deposition by Chemical Bath Deposition method. With the oxidant, a more compact CdS films were fabricated. The average grain size decreases from 88 nm to 15 nm with the increasing concentration of H2O2 that was used in CdS deposition. The growth mechanism has been discussed in view of the reaction...

We report a novel method to fabricate sectionalized hydrophobic/hydrophilic nanochannel. Photolithography, dry/wet etching, aligned anodic bonding and selective modification were utilized to fabricate nanochannel with four-sided surface patterns. Nanofluidic behavior was investigated by pressure driven method to study the relationship between press...

In organic field-effect transistors, the first few molecular layers at the semiconductor/dielectric interface are regarded as the active channel for charge transport, thus great efforts have been devoted to the modification/optimization of molecular packing at such interfaces. Here, we report the organic monolayers with large-area uniformity and hi...

Piezoelectric response of P(VDF-TrFE), which is modulated by the dipole density due to the polarization switching on applying an electric field, allows it act as the fundamental components for electromechanical systems. As proposed since the 1970s, its polar α-phase is supposed to yield an enhanced piezoelectric activity. However, its experimental...

Flexible pressure sensors are crucial for E-skins to enable tactile sensing capabilities. However, flexible pressure sensors often exhibit high hysteretic response caused by internal and external mechanical dissipations in flexible materials. The hysteresis gives rise to reliability issues, especially in the presence of dynamic stress. In this lett...

Two dimensional (2D) molecular crystals have attracted considerable attention because of their promising potential in electrical device applications, such as high-performance field-effect transistors (FETs). However, such devices demand high voltages, thereby considerably increasing power consumption. This study demonstrates the fabrication of orga...

Nanocomposite Si1-xGex films are deposited by dual-source jet-type inductively coupled plasma chemical vapor deposition (jet-ICPCVD). The segregations and desorptions of Ge atoms, which dominate the structural evolutions of the films during high-temperature annealing, are investigated. When the annealing temperature (Ta) is 900 °C, the nanocomposit...