Photochromic Molecules Research Articles

Ultra‐High Secure Holographically Steganographic Array with Spatiotemporal Dual‐Encryption Keys

AbstractIndependently‐manipulated optical encryption has attracted great attention due to its high security and multiple application scenarios. Although photochromic molecules have become preferred holographic display units, the integration of dynamic modulation both in hologram and fluorescence for orthogonal encryption is still challenged. Herein, a latticed holographically steganographic array is constructed by incorporating a plasticizer (tri‐o‐cresyl phosphate, TOCP) into spirooxazine (SO) based polymers, thereby modulating the isomerization rate and the UV‐fluorescence kinetics between SO and merocyanine (MC). The period to reach fluorescence saturated value for each information bit in the latticed device can be widely modulated between 60 and 1700 s. Based on the property, only through ultraviolet stimulation can array information gradually be converted from spatial lattice coordinates to holographic display time. Then, a hidden 3D image can be determined from rapidly updatable reconstructed hologram video with refresh rate 1.125 Hz by the above spatiotemporal dual‐encryption keys. This work provides a bright path for the ultra‐high safety steganography and adaptive stereoscopic imaging.

Investigation on luminescence photoswitching stability in diarylethene-perovskite quantum dot hybrids.

Perovskite quantum dots (pQDs) have gathered a lot of attention because of their outstanding optoelectronic properties. Photoswitchable pQDs have the potential for application in single particle optical memories and bio-imaging. Hybrids of photochromic diarylethenes (DAE) and pQDs show a luminescence photoswitching property, however, the cycle stability in such systems is low because of photoinduced electron transfer (PET) from pQDs to DAE. In this study, various hybrids of DAEs and pQDs with different spacer lengths between the pQD donors and DAE acceptors were synthesized and their stability towards multiple cycles of luminescence photoswitching was evaluated. It was found that the electron transfer pathway can be blocked and very stable switchable hybrids can be produced when the distance between the donors and acceptors was long enough. Furthermore, the effect of softness of the basic ligands and the synthesis method of the pQDs on the cycle stability of the hybrids were investigated. The findings of this study suggest that the photoswitching stability can be improved in hybrid systems by proper molecular design of the photochromic molecule.

Fabrication and Characterization of Co-Sensitized Dye Solar Cells Using Energy Transfer from Spiropyran Derivatives to SQ2 Dye

We developed dye-sensitized solar cells (DSSCs) using 1,5-carboxy-2-[[3-[(2,3-dihydro-1,1-dimethyl-3-ethyl-1H-benzo[e]indol-2-ylidene)methyl]-2-hydroxy-4-oxo-2-cyclobuten-1-ylidene]methyl]-3,3-dimethyl-1-octyl-3H-indolium and 1,3,3-trimethyl indolino-6′-nitrobenzopyrylospiran. The DSSCs incorporate photochromic molecules to regulate photoelectric conversion properties. We irradiated photoelectrodes adsorbed with SQ2/SPNO2 using both UV and visible light and observed the color changes in these photoelectrodes. Following UV irradiation, the transmittance at 540 nm decreased by 20%, while it increased by 15% after visible light irradiation. This indicates that SPNO2 on the DSSCs is photoisomerized from the spiropyran form (SP) to the photomerocyanine (PMC) form under UV light. The photoelectric conversion efficiency (η) of the DSSCs increased by 0.15% following 5 min of UV irradiation and decreased by 0.07% after 5 min of visible light irradiation. However, direct electron injection from PMC seems challenging, suggesting that the mechanism for improved photoelectric conversion in these DSSCs is likely due to Förster resonance energy transfer (FRET) from PMC to the SQ2 dye. The findings suggest that the co-sensitization of DSSCs by PMC-SQ2 and SQ2 alone, facilitated by their respective photoabsorption, results in externally responsive and co-sensitized solar cells. This study provides valuable insights into the development of advanced DSSCs with externally controllable photoelectric conversion properties via the strategic use of photochromic molecules and energy transfer mechanisms, advancing future solar energy applications.

Polymer-stabilized cholesteric liquid crystals with multi-state reversibility for applications in advanced smart adjustable anti-counterfeiting and energy-saving displays

The creation of an anti-counterfeiting material with reflection color, fluorescence, infrared imaging, and electrical property information will increase the level of anti-counterfeiting. However, the creation of such a material has proved to be extremely challenging. In this study, twin anti-counterfeiting labels with intelligently tunable patterns were obtained through a strategy of PMMA loaded chiral molecules via diffusing on the micrometer scale. In order to enhance anti-counterfeiting ability, the multi-mode intelligently modulated advanced anti-counterfeiting material was obtained through the strategy of introducing photo-isomerizing dithienylethene and infrared-shielding Cs0.33WO3 nanoparticles. This material can be reversibly converted into fluorescent, reflected colors, infrared, and electrical characteristic signals. The encrypted information is displayed with red fluorescence under UV light irradiation. Furthermore, the encrypted information can be reversibly displayed and erased under repeated stimulation by voltage and pressure, heating and cooling, UV, visible and near infrared (NIR) light. The aim of our work is to create a simple method to prepare complex patterns of structural and fluorescent color anti-counterfeiting films with the improved anti-counterfeiting capability. Based on this, the strategy of co-doping fluorescent molecules and photochromic molecules in liquid crystals combined with etching technology has realized a multiple anti-counterfeiting mode with a higher level of security. The advanced multiple anti-counterfeiting mode can output encrypted information of multiple states which will greatly improve the level of anti-counterfeiting. In terms of display, we obtained billboards with complex patterns, price intelligently tunable and full-color display by diffusion S5011 in liquid crystals, thus extending their application in the field of electronic shelf labels.

Reversible Multi-Color optical switch utilizing tetraphenylethylene and spiropyran Complexes: Applications in advanced information encryption

In this paper, we introduced a strategic methodology to obtain time-resolved encryption utilizing a new technique. This method utilizes a reversible supramolecular optical switch, which is based on complexes consisting of tetraphenylethylene and spiropyran. Notably, these components are separately attached at the focal point of the same cholesterol-based unit, wherein the cholesterol-based unit can provide the essential driving forces to form complexes. A series of complexes were prepared with varying molar ratios (TPE/SP), allowing for the tuning of fluorescence emission. The supramolecular system leverages hydrogen bonding, van der Waals forces, and other non-covalent interactions to orchestrate the collaboration between the fluorophores (tetraphenylethylene) and the photochromic molecule (spiropyran). This coordination results in exceptional photochromic attributes, including rapid response, high contrast, and the capability to regulate fluorescence. The system is capable of achieving tunable dynamic fluorescence emission that transitions from brilliant blue to light purple and finally to red through fluorescence resonance energy transfer (FRET) after successive irradiation periods. Additionally, by fine-tuning the ratio of tetraphenylethylene to spiropyran, different dynamic fluorescence emission can be precisely manipulated. It is rarely reported that complexes accomplish time-dependent fluorescence emission with high-contrast. We are confident that the complexes, grounded on cholesterol unit, hold promise for broader applicability in developing innovative time-dependent fluorescent materials. Such materials can be effectively utilized for time-dependent information encryption, thereby bolstering security measures against unauthorized access.

Light-Modulated Humidity Sensing in Spiropyran Functionalized MoS2 Transistors.

The optically tuneable nature of hybrid organic/inorganic heterostructures tailored by interfacing photochromic molecules with 2D semiconductors (2DSs) can be exploited to endow multi-responsiveness to the exceptional physical properties of 2DSs. In this study, a spiropyran-molybdenum disulfide (MoS2) light-switchable bi-functional field-effect transistor is realized. The spiropyran-merocyanine reversible photo-isomerization has been employed to remotely control both the electron transport and wettability of the hybrid structure. This manipulation is instrumental for tuning the sensitivity in humidity sensing. The hybrid organic/inorganic heterostructure is subjected to humidity testing, demonstrating its ability to accurately monitor relative humidity (RH) across a range of 10%-75%. The electrical output shows good sensitivity of 1.0% · (%) RH-1. The light-controlled modulation of the sensitivity in chemical sensors can significantly improve their selectivity, versatility, and overall performance in chemical sensing.

Reversible Switching of Light‐Gated Organic Transistors Employing Dihydroazulene/Vinylheptafulvene Photo‐/Thermochromic Molecules

AbstractAn innovative possibility to introduce additional functionality to organic field‐effect transistors (OFETs) is to employ photochromic molecules, which undergo reversible isomerization under applied stimuli such as irradiation with specific wavelengths. As a result, the transistors not only can be switched on/off by the applied voltages, they can also be programmed by alternate triggers, such as light. Here, reversible switching of OFETs is presented by blending various dihydroazulene/vinylheptafulvene photoswitches into polythiophene‐based conjugated polymers. In result, the transfer characteristics of the transistors are altered significantly through UV irradiation. In contrast to current literature on different photoswitches such as spiropyrans or diarylethenes, the backreaction is induced thermally and not via visible light irradiation and reproducibly yields the pristine transistor characteristics. This reversible switching upon alternating UV irradiation and thermal annealing is quantified by figures of merit such as the magnitude of drain current, threshold voltage, and subthreshold swing. Irradiating the devices with different doses of UV light shows that the magnitude of switching directly depends on the respective UV dose, hence enabling a multi‐level electronic system. Furthermore, long‐term cyclability over 100 steps of repeated UV light exposure and thermal annealing is demonstrated.

All-optical organic photochemical integrated nanophotonic memory: low-loss, continuously tunable, non-volatile

Controlling changes in the optical properties of photonic devices allows photonic integrated circuits (PICs) to perform useful functions, leading to a large breadth of applications in communications, computing, and sensing. Many mechanisms to change optical properties exist, but few allow doing so in a reversible, non-volatile manner. Without such mechanisms, power inefficiencies and use of external memory are inevitable. In this work, we propose and experimentally demonstrate reversible, non-volatile phase actuation of a silicon nitride PIC with thermally stable photochromic organic molecules vapor-deposited within a slot waveguide structure. The use of a high-core-index platform allows the photochemical phase actuation of a planar-resonator-based photonic memory unit, which enables positive and negative signal weighting and permits integrated spectroscopic analysis. We show properties of this all-optical memory for a silicon photonics platform, including low loss in the optical C-band, first-order photokinetics of the photoconversion, bidirectional scalable switching, and continuous tuning. Such features are critical for memories in analog applications such as quantum, microwave, and neuromorphic photonics, where bipolar weights, low loss, and precision are paramount. More generally, this work suggests that back-end-of-line-compatible vapor deposition of organic molecules into silicon photonic circuits is promising to introduce non-silicon-native functionality.

Photochromic Spiropyran-Based Dual-Emitting Luminescent Hybrid Films for Dynamic Information Anticounterfeiting.

Photoluminescent materials are widely used for information storage and anticounterfeiting, while most of them have the disadvantages of static information performance and weak processability, which is still a challenging task in developing dynamic anticounterfeiting materials with high security levels. Herein, we fabricated a novel photostimuli-responsive dual-emitting luminescent material UPTES-SPn-Tb-hfa, which was obtained by introducing the photochromic molecule spiropyran (SP) and lanthanide complex (Tb-hfa) into a siloxane-polyether matrix using the sol-gel process. Due to the conformation-dependent photochromic fluorescence resonance energy transfer between the Tb-hfa donor and SP acceptor, the ring-closing (SP)/ring-opening (MC) isomerization of the SP unit leads to a reversible luminescence switching in UPTES-SPn-Tb-hfa. This composite material has great potential for advanced anticounterfeiting because of the advantage of rapidly repeatable encryption/decryption for at least 8 times and dynamic luminescent colors within 15 s. In addition, due to its two luminescent centers (Tb3+ and MC), the luminescent color of this material can be regulated by 254 and 365 nm UV-light irradiation, which facilitates the design of multicolored anticounterfeiting labels. Our work presents a novel design methodology to fabricate dynamic anticounterfeiting materials, significantly enhancing the security of anticounterfeiting applications.

Photo-Modulation of Atomically Thin Molybdenum Diselenides Functionalized with Photochromic Molecules

Two-dimensional (2D) transition metal dichalcogenide semiconductors have garnered significant attention due to their extraordinary electrical and optical properties. It has been increasingly important to develop strategies for modulating their properties. A number of methods have been introduced, including doping, electric and magnetic fields, mechanical strain, etc. Herein, we report a novel approach of using photochromic molecules to modulate optoelectronic properties of monolayer MoSe2 with light. We have synthesized photochromic diarylethene (DAE) molecules that can switch between two isomeric forms, referred to as open and closed, under UV and visible light, respectively. The DAE molecules formed a uniform layer with a thickness of approximately 2 nm on monolayer MoSe2. Our density functional theory (DFT) calculations suggest that the TMD and DAE will align their band energy levels such that UV irradiation moves the lowest unoccupied molecular orbital (LUMO) energy of DAE in between the conduction band minimum (CBM) and valence band minimum (VBM) of MoSe2. This will facilitate photoexcited electron transfer from MoSe2 to DAE LUMO. Experimentally, we have confirmed our predictions by observing a strong quenching of photoluminescence (PL) and an increase of electrical conductivity in MoSe2. In contrast, visible light induced isomerization to the open form of DAE and expanded its energy levels, moving the LUMO level above the MoSe2 CBM. Therefore, the PL was retained and there was no significant change in electrical conductivity. We showed that this photoswitching can dynamically modulate the optoelectronic properties by demonstrating multiple cycles of PL emission and quenching, by alternating UV and visible light repeatedly. Lastly, our Kelvin probe force microscopy (KPFM) revealed that the potential of MoSe2 monolayers can also be modulated with photochromic molecules and external light irradiation. Our work elucidates photo-processes and exciton mechanisms at the hybrid interfaces and lays the foundation for novel applications including new phototransistors and other 2D optoelectronic devices.

Stepwise Photochromism of Large Macrocycles Incorporating Two Negative Photochromic Units.

Macrocyclic photochromic molecules incorporating multiple photochromic units are known to exhibit cooperative and nonlinear photochromic reactions among distinct photochromic components. While extensive research has concentrated on positive photochromic molecules, this study presents a pioneering attempt in synthesizing macrocyclic photochromic molecules that integrate negative photochromic units. Binaphthyl-bridged phenoxyl imidazolyl radical complex, BN-PIC, exhibits unique negative photochromism in which the thermally stable colored isomer converts to the metastable colorless isomer via a short-lived biradical upon visible-light irradiation. Macrocyclic biphotochromic molecules incorporating two BN-PIC units were synthesized and the effects of ring strain on the photochromic properties including the photoconversion efficiencies and the rates of the thermal reverse reaction were investigated. The photokinetic study of these macrocyclic biphotochromic molecules demonstrated that the structural distortion of the ring caused by the isomerization of one photochromic unit significantly influenced the photoisomerization efficiency and the rate of the thermal reverse reaction of the other photochromic unit.

All-visible-light-driven salicylidene schiff-base-functionalized artificial molecular motors

Light-driven rotary molecular motors are among the most promising classes of responsive molecular machines and take advantage of their intrinsic chirality which governs unidirectional rotation. As a consequence of their dynamic function, they receive considerable interest in the areas of supramolecular chemistry, asymmetric catalysis and responsive materials. Among the emerging classes of responsive photochromic molecules, multistate first-generation molecular motors driven by benign visible light remain unexplored, which limits the exploitation of the full potential of these mechanical light-powered systems. Herein, we describe a series of all-visible-light-driven first-generation molecular motors based on the salicylidene Schiff base functionality. Remarkable redshifts up to 100 nm in absorption are achieved compared to conventional first-generation motor structures. Taking advantage of all-visible-light-driven multistate motor scaffolds, adaptive behaviour is found as well, and potential application in multistate photoluminescence is demonstrated. These functional visible-light-responsive motors will likely stimulate the design and synthesis of more sophisticated nanomachinery with a myriad of future applications in powering dynamic systems.

Mechanical Effect Produced by Photo‐Switchable Reactions: Insights from Molecular Simulations

AbstractLight‐responsive shape‐changing polymers are photonastic materials: they can convert light into mechanical energy through macroscopic transformations. Indeed, photochromic molecules embedded in these polymer films present light‐induced structural modifications that can trigger a significant macroscopic deformation. In this theoretical study based on molecular dynamics simulations, analysis tools ranging from atomic to supramolecular scales are developed to investigate this photonastic phenomenon. To this purpose, a model system built upon an azobenzene photochrome embedded in different environments (tetrahydrofuran, cis‐1,4‐polybutadiene and hydroxyl‐terminated polybutadiene) is considered. First, the impact of the environment on the photochrome properties is discussed through the analysis of the structural properties, ultra‐violet visible (UV–vis) absorption spectra and dynamical properties of the photoswitch. Then, the impact of the presence of the photochrome on the polymer is studied. At the atomic scale, the radial distribution functions show some differences between the cis and trans isomers due to geometrical effects. At the molecular scale, the analysis of the size and shape of the polymer chains reveals that the photochrome has no impact on the chain properties. Finally, at the macroscopic scale, the cohesive energy density shows that the polymer is stabilized by the presence of photochrome molecules.

Click generated photochromic naphthalenediimide-dithienylethene diad: Application in deciphering secret codes

Photochromic molecules with efficient fluorescence switching capability remain a core research interest among the scientific community for the application in security technologies and anti-counterfeiting measures. A dithienylethene-naphthalene diimide diad was designed and synthesized using Cu(I) catalysed click reaction between a fluorescent core substituted naphthalene diimide (cNDI) and photochromic dithienylethene (DTE) molecule, which demonstrated excellent photocyclization (ksolution = 0.0359 s−1, ksolid = 0.0122 s−1) and photocycloreversion (ksolution = 0.01737 s−1, ksolid = 0.00456 s−1) dynamics with high fluorescence quantum yield (5o ΦF = 0.39, PSS ΦF = 0.05). The fluorescence property of the molecule was switched ‘on-off’ by UV and visible light irradiation respectively via Förster resonance energy transfer (FRET) mechanism in solution state as well as in solid state, which was further corroborated with DFT studies. In view of efficient fluorescence switching behaviour and high fatigue resistance properties (25 cycles), the molecule was successfully applied in secret code encryption-decryption purposes using barcode demonstrating real-life applicability of the molecule in security technologies.

Photochromic Carbon Nanomaterials: An Emerging Class of Light-Driven Hybrid Functional Materials.

Photochromic molecules have remarkable potential in memory and optical devices, as well as in driving and manipulating molecular motors or actuators and many other systems using light. When photochromic molecules are introduced into carbon nanomaterials (CNMs), the resulting hybrids provide unique advantages and create new functions that can be employed in specific applications and devices. This review highlights the recent developments in diverse photochromic CNMs. Photochromic molecules and CNMs are also introduced. The fundamentals of different photochromic CNMs are discussed, including design principles and the types of interactions between CNMs and photochromic molecules via covalent interactions and non-covalent bonding such as π-π stacking, amphiphilic, electrostatic, and hydrogen bonding. Then the properties of photochromic CNMs, e.g., in photopatterning, fluorescence modulation, actuation, and photoinduced surface-relief gratings, and their applications in energy storage (solar thermal fuels, photothermal batteries, and supercapacitors), nanoelectronics (transistors, molecular junctions, photo-switchable conductance, and photoinduced electron transfer), sensors, and bioimaging are highlighted. Finally, an outlook on the challenges and opportunities in the future of photochromic CNMs is presented. This review discusses a vibrant interdisciplinary research field and is expected to stimulate further developments in nanoscience, advanced nanotechnology, intelligently responsive materials, and devices.

A Hexaarylbiimidazole‐Terarylene Hybrid: Visible‐to‐NIR‐II Absorption via Sequential Photochromic Reactions

A synergetic interaction between two or more photochromic chromophores has a potential to achieve advanced photochemical properties beyond conventional photochromic molecules and to realize photochemical control of complex systems using only a single molecule. Herein, we report a hybrid photochromic molecule consisting of hexaarylbiimidazole (HABI) and terarylene that exhibits multi‐state photochromism. The biphotochrome hybrid shows four‐state photochromic reaction involving sequentially proceeding photoreactions. The UV or visible light irradiation to the biphotochrome leads to the C–N bond breaking reaction of the HABI in preference to the ring‐closing reaction of the 6π‐electron system in the terarylene unit, leading two terarylene radical molecules. The photogenerated terarylene radical further exhibits the 6π‐electrocyclization reaction by UV irradiation. The delocalized π‐radical on the closed‐ring form of the terarylene is efficient to enhance the photosensitivity to the NIR‐I and ‐II region. Furthermore, a recombination reaction of radicals between the open‐ and closed‐ring isomers of terarylene affords an unprecedented photochromic dimer as a structural isomer of the initial molecule. This is a consequence of the sequential hybrid photochromic system involving the HABI and terarylene units.

A Hexaarylbiimidazole-Terarylene Hybrid: Visible-to-NIR-II Absorption via Sequential Photochromic Reactions.

A synergetic interaction between two or more photochromic chromophores has a potential to achieve advanced photochemical properties beyond conventional photochromic molecules and to realize photochemical control of complex systems using only a single molecule. Herein, we report a hybrid photochromic molecule consisting of hexaarylbiimidazole (HABI) and terarylene that exhibits multi-state photochromism. The biphotochrome hybrid shows four-state photochromic reaction involving sequentially proceeding photoreactions. The UV or visible light irradiation to the biphotochrome leads to the C-N bond breaking reaction of the HABI in preference to the ring-closing reaction of the 6π-electron system in the terarylene unit, leading to two terarylene radical molecules. The photogenerated terarylene radical further exhibits the 6π-electrocyclization reaction by UV irradiation. The delocalized π-radical on the closed-ring form of the terarylene is efficient to enhance the photosensitivity to the NIR-I and -II region. Furthermore, a recombination reaction of radicals between the open- and closed-ring isomers of terarylene affords an unprecedented photochromic dimer as a structural isomer of the initial molecule. This is a consequence of the sequential hybrid photochromic system involving the HABI and terarylene units.

Incorporation of organic photochromic molecules in mesoporous silica materials: Synthesis and applications

Abstract The ability to control the function and structure of some promising nanosystems using an external stimulus is attractive research to develop programmable and reconfigurable intelligent nanomaterials. The focal point of this review is the silicon-based nanoporous materials, and particularly the mesoporous silica materials (MSMs) class (pore size: 2–50 nm), due to their important intrinsic properties, such as high surface area, highly ordered nanostructure, narrow pore size distribution, various dimensions (one-dimensional, two-dimensional, and three-dimensional), and easily functionable. One of the most essential organic components that can be incorporated in MSMs is organic photochromic molecules (OPMs), such as azobenzene, stilbene, dithienylethenes, and spiropyrans. OPMs can be incorporated into MSMs, to form photochromic mesoporous organosilica materials (PMOMs), in two different ways: physical (non-covalent immobilization) or chemical (covalent immobilization) binding. PMOMs are considered smart nanomaterials because they have the ability to undergo reversible changes in the solid state when exposed to an external electromagnetic radiation. PMOMs have been the subject of many research studies during the last decade due to their potential applications, especially as chemosensors. This review discusses the main families of OPMs, their incorporation into MSMs using different methods, and the applications of some PMOMs as chemosensors.

Photorewriting, Time-Resolved Encryption, and Unclonable Anticounterfeiting with Artificial Intelligence Authentication via a Reversible Photoswitchable System.

In the fields of photolithographic patterning, optical anticounterfeiting, and information encryption, reversible photochromic materials with solid-state fluorescence are emerging as a potential class of systems. A design strategy for reversible photochromic materials has been proposed and synthesized through the introduction of photoactive thiophene groups into the molecular backbone of aryl vinyls, compounds with unique aggregation-induced emission properties, and solid-state reversible photocontrollable fluorescence and color-changing properties. This work develops novel photochromic inks, films, and cellulose hydrogels for enhancing the security of information encryption and anticounterfeiting technologies. They achieve rapid and reversible color change under ultraviolet light irradiation. Dependent upon the rate of color change, higher levels of time-resolved security can be achieved. This feature is important for enhancing the confidentiality of encrypted information and the reliability of security labels. Color-changing cellulose hydrogels, inks, and films consisting of three photochromic fluorescent molecules have quick photoactivity, great photoreversibility and photostability, and good processability, making them ideal for time-delayed anticounterfeiting and smart encryption. Furthermore, specialized algorithms are used to construct convolutional neural networks, and image analysis is performed on these systems, thus solving the current problem of the time-consuming information decryption process. This artificial intelligence method offers new opportunities for enhanced data encryption.

Li Promoting Long Afterglow Organic Light-Emitting Transistor for Memory Optocoupler Module.

The artificial brain is conceived as advanced intelligence technology, capable to emulate in-memory processes occurring in the human brain by integrating synaptic devices. Within this context, improving the functionality of synaptic transistors to increase information processing density in neuromorphic chips is a major challenge in this field. In this article, Li-ion migration promoting long afterglow organic light-emitting transistors, which display exceptional postsynaptic brightness of 7000cdm-2 under low operational voltages of 10V is presented. The postsynaptic current of 0.1mA operating as a built-in threshold switch is implemented as a firing point in these devices. The setting-condition-triggered long afterglow is employed to drive the photoisomerization process of photochromic molecules that mimic neurotransmitter transfer in the human brain for realizing a key memory rule, that is, the transition from long-term memory to permanent memory. The combination of setting-condition-triggered long afterglow with photodiode amplifiers is also processed to emulate the human responding action after the setting-training process. Overall, the successful integration in neuromorphic computing comprising stimulus judgment, photon emission, transition, and encoding, to emulate the complicated decision tree of the human brain is demonstrated.