Human-interactive displays (HIDs) have advanced the ability to visualize a spectrum of phenomena, ranging from tangible to imperceptible. Within the realm of HIDs, the role of infrared technologies stands out, with applications spanning from imaging to biomedicine. Here, we introduce a novel near infrared (NIR)-interactive synaptic display based on alternating current electroluminescence (ACEL), with a unique near infrared-responsive layer comprising from a blend of MXene and a polymer electrolyte. Our synaptic display transcends mere responsiveness to NIR exposure, by leveraging synaptic properties to visualize NIR exposure, thereby successfully realizing a neuromorphic display. Utilizing this system, we present an intelligent wound healing device through neuromorphic photothermal therapy, demonstrating its potential as a personalized treatment device. Moreover, we demonstrate the potential of this display in visualizing infrared radiation, highlighting its promising role in the ever-evolving field of HIDs.
Artificial photonic synapses, designed for emerging photo-interactive neuro-computing technologies, have been developed with area-density-tunable perovskite nano-cone arrays within a self-assembled block copolymer (BCP). These arrays, part of a field effect transistor with a floating gate of photoreceptive perovskite crystals, can trap and release electric charges, exhibiting functions like paired-pulse facilitation and long-term potentiation. Crafted using an off centered spin coating process, the perovskite floating gate emulates the human retina's position-dependent spatial distribution of cones. Arranged in 60 × 12 arrays, the synapse devices serve dual functions as receptors and synapses, demonstrating AI capabilities with pattern recognition accuracy up to 90%, as tested with the Modified National Institute of Standards and Technology handwritten digit pattern recognition test.
Perovskite light-emitting diodes (PeLEDs) are considered as promising candidates for next-generation solution-processed full-color displays. However, the external quantum efficiencies (EQEs) and operational stabilities of deep-blue (<460 nm) PeLEDs still lag far behind their red and green counterparts. Herein, a rapid crystallization method based on hot-antisolvent bathing is proposed for realization of deep-blue PeLEDs. By promoting immediate removal of the precursor solvent from the wet perovskite films, development of the quasi-two-dimensional (2D) Ruddlesden–Popper perovskite (2D-RPP) crystals with n values >3 is hampered completely, so that phase-pure 2D-RPP films with bandgaps suitable for deep-blue PeLEDs can be obtained successfully. The uniquely developed rapid crystallization method also enables formation of randomly oriented 2D-RPP crystals, thereby improving the transfer and transport kinetics of the charge carriers. Thus, high-performance deep-blue PeLEDs emitting at 437 nm with a peak EQE of 0.63% are successfully demonstrated. The color coordinates are confirmed to be (0.165, 0.044), which match well with the Rec.2020 standard blue gamut and have excellent spectral stability.
Human-interactive displays (HIDs) facilitate the visualization of sensible information such as touch, smell, and sound and have attracted significant interest owing to their potential in emerging IoT-connected wearable electronics. Furthermore, the visualization of phenomena that is rarely sensible, such as magnetic fields, ultrasonic waves, and odorless toxic gases or liquids, can further broaden the utilization of HIDs. Field-induced electroluminescence (EL) of either organic or inorganic fluorescent materials under alternating current (AC) has been extensively studied and its unique device architecture in which an emitting layer is separated with an insulator from electrode offers a new platform for designing and developing emerging HIDs. Here, we present various sensory and extra-sensory interactive displays based on AC EL.
Ordered nanostructured crystals of thin perovskites films are of great interest to researchers because of the dimensional-dependence of their photoelectronic properties for developing the perovskites with novel properties. In this presentation, both top-down and bottom-up approaches for fabricating nanostructured perovskite films are demonstrated. First, a variety of micro/nanopatterns of a perovskite film are fabricated by either microimprinting or transfer-printing a thin spin-coated precursor film in soft-gel state with a topographically pre-patterned polymer mold, followed by thermal treatment for complete conversion of the precursor film to a perovskite one. Second, we also demonstrate a simple and robust route, involving the controlled crystallization of the perovskites templated with a self-assembled block copolymer (BCP), for fabricating nanopatterned perovskite films with various shapes and nanodomain sizes. When the precursor ion solution of a perovskite and poly(styrene)-block-poly(2-vinylpyridine) (PS-b-P2VP) was spin-coated on the substrate, a nanostructured BCP was developed by microphase separation. Spontaneous crystallization of the precursor ions preferentially coordinated with the P2VP domains yielded ordered nanocrystals with various nanostructures. The nanopatterned perovskites showed significantly enhanced photoluminescence (PL) with high resistance to both humidity and heat due to geometrically confining crystals in and passivation with the P2VP chains. The self-assembled perovskite films with high PL performance provided a facile control of color coordinates by color conversion layers in blue-emitting devices for cool-white emission.
Development of stimuli-interactive sensing display capable of spontaneously visualizing various external human sensible inputs has been of great interest and tremendous efforts are devoted to the visualization of nonvisible human senses such as touch, smell, taste, and sound. Field induced electroluminescence of either organic or inorganic fluorescent materials under alternating current (AC) has been extensively studied and its unique device architecture in which an emitting layer is separated with an insulator from electrode offers a new platform for designing and developing emerging stimuli-interactive displays. In this presentation, high-performance field-induced AC polymer electroluminescence (AC-PEL) devices are demonstrated with high brightness, high efficiency and color and intensity-tunability. We also present a pressure interactive AC display sensor that allows for both sensing and visualisation of pressure. Light emission upon exposure to an AC field between two electrodes is controlled by the capacitance change of the insulator arising from the pressure applied on top. Besides capacitive pressure sensing, our EL sensor allows for direct visualisation of the static and dynamic information of position, shape, and size of a pressurising object on a non-pixelated single device platform. Finally, the presentation shows that simultaneous sensing and visualization of the conductive substance is achieved when the conductive object is coupled with the light emissive material layer on our novel parallel-type AC-PEL device. A variety of conductive materials can be detected regardless of their work functions, and thus information written by a conductive pen is visualized, as is a human fingerprint with natural conductivity.
Field induced electroluminescence of either organic or inorganic fluorescent materials under alternating current (AC) has been of great attention as a potential candidate for next generation displays, lightings and sensors. Unique device architecture in which an emitting layer is separated with an insulator from electrode offers a new platform for designing and developing a variety of types of ELs. Here, we demonstrate high-performance field-induced AC polymer electroluminescence (AC-PEL) devices with high brightness, high efficiency and color-tunability. We also present a non-volatile EL memory in which arbitrarily chosen EL states are programmed and erased repetitively with long EL retention. Our memory is based on utilizing the built-in electric field arising from the remanent polarization of a ferroelectric polymer which in turn controls the carrier injection of an AC-PEL device. The device exhibits two distinctive non-volatile EL intensities at constant reading AC voltage, depending upon the programmed direct current (DC) voltage on the ferroelectric layer. DC programmed and AC read EL memories are also realized with different EL colors of R, G and B. Finally, we show that simultaneous sensing and visualization of the conductive substance is achieved when the conductive object is coupled with the light emissive material layer on our novel parallel-type AC-PEL device. A variety of conductive materials can be detected regardless of their work functions, and thus information written by a conductive pen is clearly visualized, as is a human fingerprint with natural conductivity.
One of a wide-bandgap semiconductor, Zinc oxide (ZnO) has a near ultraviolet bandgap (3.37 eV) and an exciton binding energy of 60 meV at room temperature (RT), and has several favorable properties, such as high electron mobility, high oscillator strength, and good transparency. In the photoluminescence (PL) spectra of ZnO nanoparticles, the near band edge ultraviolet (UV) emission at 378 nm relevant to direct bandgap of ZnO, and blue light emissions centered at 410, 435, and 465 nm corresponding to Zn interstitial (Zni) to valence band maximum (VBM), and to Zn vacancies (VZn) and green light emission at 540 nm corresponding to conduction band maximum (CBM) to oxygen vacancy (Vo). Ultra-small size quasi consolidated ZnO-graphene nanoparticles was synthesized in which graphene outer layer was chemically attached with ZnO inner core. After attaching graphene to ZnO, green emission completely disappeared whereas the intensity of blue emission was greatly increased. Enhanced blue emission could be well described by both fast electron transfer from CBM of ZnO to graphene having similar molecular energy level with Zni and transition to VBM and Vzn. Glass/ITO/PEDOT:PSS/poly-TPD/ZnO-graphene/Cs2CO3/Al were fabricated and showed the blue emission centered at 435 nm with FWHM of about 90 nm.
1D photonic crystals based on the periodic stacking of two different dielectric layers have been widely studied due to their potential use in low-power reflective mode displays, e-books and sensors, but the fabrication of mechanically flexible polymer structural color (SC) films, with electro-active color switching, remains challenging. Here, we demonstrate free-standing electric field tunable ionic liquid swollen block copolymer films. Placement of a polymer/ionic liquid (IL) film-reservoir adjacent to a self-assembled poly(styrene-block-quaternized 2vinyl pyridine) (PS-b-QP2VP) copolymer SC film allowed the development of R, G and B full-color SC block copolymer films by swelling of the QP2VP domains by the ionic liquid associated with water molecules. The IL-polymer/BCP SC film is mechanically flexible with excellent color stability over several days at ambient conditions. The selective swelling of the QP2VP domains could be controlled by both the ratio of the IL to a polymer in the gel-like IL reservoir layer and by an applied voltage in the range of -3V to +6V using a metal/IL reservoir/SC film/IL reservoir/metal capacitor type device.
Resistive random-access memory (RRAM) is a candidate next generation nonvolatile memory due to its high access speed, high density and ease of fabrication. Especially, cross-point-access allows cross-bar arrays that lead to high-density cells in a two-dimensional planar structure. Use of such designs could be compatible with the aggressive scaling down of memory devices, but existing methods such as optical or e-beam lithographic approaches are too complicated. One-dimensional inorganic nanowires (i-NWs) are regarded as ideal components of nanoelectronics to circumvent the limitations of conventional lithographic approaches. However, post-growth alignment of these i-NWs precisely on a large area with individual control is still a difficult challenge.
Here, we report a simple, inexpensive, and rapid method to fabricate two-dimensional arrays of perpendicularly-aligned, individually-conductive Cu-NWs with a nanometer-scale CuxO layer sandwiched at each cross point, by using an inorganic-nanowire-digital-alignment technique (INDAT) and a one-step reduction process. In this approach, the oxide layer is self-formed and patterned, so conventional deposition and lithography are not necessary. INDAT eliminates the difficulties of alignment and scalable fabrication that are encountered when using currently-available techniques that use inorganic nanowires. This simple process facilitates fabrication of cross-point nonvolatile memristor arrays. Fabricated arrays had reproducible resistive switching behavior, high on/off current ratio (Ion/Ioff) ~10 6 and extensive cycling endurance. This is the first report of memristors with the resistive switching oxide layer self-formed, self-patterned and self-positioned; we envision that the new features of the technique will provide great opportunities for future nano-electronic circuits.
Self assembly driven by complicated but systematic hierarchical interactions offers a qualified alternative for fabricating functional micron or nanometer scale pattern structures that have been potentially useful for various organic and nanotechnological devices. Self assembled nanostructures generated from synthetic polymer systems such as controlled polymer blends, semi-crystalline polymers and block copolymers have gained a great attention not only because of the variety of nanostructures they can evolve but also because of the controllability of these structures by external stimuli. In this presentation, various novel photo-electronic materials and devices are introduced based on the solution-processed low dimensional nanomaterials such as networked carbon nanotubes (CNTs), reduced graphene oxides (rGOs) and 2 dimensional transition metal dichalcogenides (TMDs) with self assembled polymers including field effect transistor, electroluminescent device, non-volatile memory and photodetector. For instance, a nanocomposite of networked CNTs and a fluorescent polymer turned out an efficient field induced electroluminescent layer under alternating current (AC) as a potential candidate for next generation displays and lightings. Furthermore, scalable and simple strategies employed for fabricating rGO as well as TMD nanohybrid films allowed for high performance and mechanically flexible non-volatile resistive polymer memory devices and broad band photo-detectors, respectively.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.