Effects of electron transport layer thickness on light extraction in corrugated OLEDs.

This study reported the effects of electron transport layer (ETL) thickness on light extraction in corrugated organic light-emitting diodes (OLEDs) and each layer in OLEDs exhibited a periodical corrugated structure, which was determined by depositing thin films on a glass substrate with a nanoimprinted blazed grating structure. The insight is that light extraction in corrugated OLEDs significantly depends on the ETL thickness. Varying the ETL thickness changed the distribution of carrier recombination and led to exciton formation and optical interference, thereby resulting in different attribution of optical loss modes in OLEDs, which increased or even decreased light extraction and device efficiency. Trapped light extraction from the surface plasmon polariton (SPP) and waveguide (WG) modes was identified by splitting the light into transverse electric and transverse magnetic emissions. Thus, the contributions from the individual SPP and WG modes to the external quantum efficiency (EQE) were distinctly clarified by comparing the experimental results with the theoretical calculations. At the ETL thickness of 115 nm, the corrugated OLED exhibited a significantly enhanced (1.83-fold) EQE compared to the planar one due to the effective extraction of trapped light from the SPP and WG modes. The EQE was enhanced by 0.5%, wherein 0.39% came from the WG mode and 0.11% came from the SPP mode.

Direct detection of virus-like particles using color images of plasmonic nanostructures.

We propose a measurement method for sensitive and label-free detections of virus-like particles (VLPs) using color images of nanoplasmonic sensing chips. The nanoplasmonic chip consists of 5×5 gold nanoslit arrays and the gold surface is modified with specific antibodies for spike protein. The resonant wavelength of the 430-nm-period gold nanoslit arrays underwater environment is about 570 nm which falls between the green and red bands of the color CCD. The captured VLPs by the specific antibodies shift the plasmonic resonance of the gold nanoslits. It results in an increased brightness of green pixels and decreased brightness of red pixels. The image contrast signals of (green - red) / (red + green) show good linearity with the surface particle density. The experimental tests show the image contrast method can detect 100-nm polystyrene particles with a surface density smaller than 2 particles/µm2. We demonstrate the application for direct detection of SARS-CoV-2 VLPs using a simple scanner platform. A detection limit smaller than 1 pg/mL with a detection time less than 30 minutes can be achieved.

Nutritional therapies in the neonatal intensive care unit and post-natal growth outcomes of preterm very low birthweight Asian infants.

AIM: A collaborative study was conducted between two Southeast Asian university hospitals to compare the nutritional intervention and growth outcomes and evaluate the extent of post-natal growth faltering (PNGF) among very low birthweight (VLBW) infants. METHODS: Data of all infants admitted during the 2011-2012 period to the two hospitals at Singapore (SG) and Malaysia (MY) were pooled and analysed. RESULTS: Of the 236 infants, SG infants received lower total protein and energy intake than MY infants (2.69 vs. 3.54 g/kg/day and 92.4 vs. 128.9 kcal/kg/day respectively; P < 0.001) in enteral feeds, with Singaporean infants predominantly fed fortified breast milk than Malaysian infants (45/48 vs. 10/41; P < 0.01). The mean weight z-score from birth to 36 weeks corrected age was significantly different (SG,-2.2 (0.9) vs. MY, -1.4 (0.7); P = 0.001). More SG than MY extremely low birthweight (ELBW) infants had severe PNGF >-2 SDS (55 vs. 16%; P = 0.001). The greater use of a diuretic in SG to treat haemodynamically significant patent ductus arteriosus (hsPDA) may have contributed to the higher PNGF rate. Mean growth velocity of at least 15 g/kg/day was attained by VLBW infants only from Day 14 and by ELBW infants only from Day 28 post-natally. Overall, severe PNGF rates (z-score change >-2 SDS at 36 weeks' corrected age) were 28.8 and 36.5% for VLBW and ELBW infants, respectively. CONCLUSIONS: Being very preterm, ELBW with hsPDA and receiving insufficient protein and energy were risk factors for severe PNGF. Increasing protein and energy content, augmenting fortification of breast milk and concentrating feed volumes, especially if there is an hsPDA, may curb severe PNGF among these infants.

Synthesis and Performance in OLEDs of Selenium-Containing Phosphorescent Emitters with Red Emission Color Deeper Than the Corresponding NTSC Standard.

The synthesis of new iridium(III) complexes containing a 2-(benzo[b]selenophen-2-yl)pyridine ligand is reported along with their photophysical, thermal, electrochemical and electroluminescent properties. These complexes are characterized by deep red phosphorescence with photoluminescence quantum yields exceeding 31% in the solid state. Solid layers of the complexes were characterized by ionization potentials of 5.17-5.27 eV and electron affinities of 2.87-2.95 eV. Their thermal and electrochemical stabilities were proved by cyclic voltammetry and thermogravimetric analysis. Deep red selenium-based iridium phosphorescent emitters were used in red electroluminescent devices which were characterized by a deep red color with Commission Internationale de l'Eclairage (CIE 1931) chromaticity coordinates (x, y) of (0.69, 0.31). This color is deeper than that defined by the red color standard (0.67, 0.33) of the National Television System Committee (NTSC) or CIE 1931 of (0.68, 0.32) of the widely known red phosphorescent emitter bis(1-phenylisoquinoline)(acetylacetonate)iridium(III) (Ir(piq)2(acac)). Using newly developed deep red iridium complexes, white hybrid wet-processable light-emitting devices were fabricated, the electroluminescence of which was characterized by a white color with a color rendering index (CRI) reaching 85. White hybrid OLEDs were obtained by mixing blue fluorescence, green thermally activated delayed fluorescence, and red phosphorescence. They showed a maximum brightness exceeding 10000 cd/m2 and a high external quantum efficiency of 6.3% as for solution-processed white devices.

Biophysical properties of striae rubra and striae alba in human skin: Comparison with normal skin.

BACKGROUND: Striae distensae are common dermal lesions that progress through two different stages: the striae rubra, which appears to be erythematous, and striae alba, which is characterized by a hypopigmented feature. The clinical characteristics between striae distensae stages and normal skin remain unknown. OBJECTIVES: We aimed to investigate the clinical characteristics according to stages of striae distensae in terms of their biophysical properties, using objective noninvasive measurements in comparison with adjacent normal skin. METHODS: Sixty-one healthy female subjects with striae distensae were included as follows: 30 with striae rubra and 31 with striae alba on the abdomen and thighs. Hydration of the epidermis and dermis, skin color brightness, and Erythema index were measured. Skin elasticity, roughness, and dermal echo-density of the skin with striae distensae and adjacent normal skin were also measured. RESULTS: Hydration of the epidermis and dermis showed no significant difference between the skin with striae distensae and normal skin. Brightness of skin with striae alba and normal skin was significantly higher than that of skin with striae rubra. Erythema index of skin with striae rubra was significantly higher than that of skin with striae alba and normal skin. Skin with striae rubra and striae alba had a rougher surface than normal skin. Elasticity and dermal echo-density were significantly lower in striae distensae skin. CONCLUSIONS: Striae rubra and striae alba had similar biophysical properties in terms of skin hydration, elasticity, roughness, and dermal density. Moreover, striae distensae have less elasticity, more roughness, and lower dermal density than normal skin.

Paracrine crosstalk between endothelial cells and melanocytes through clusterin to inhibit pigmentation.

Cutaneous vasculature systems play a role in regulating skin pigmentation. We analysed RNA sequencing data to identify novel antimelanogenic factors secreted from endothelial cells and found that one of the secreted factors, clusterin, is highly expressed by HDMECs. To investigate the paracrine effect of clusterin from HDMECs on the regulation of melanogenesis, HDMECs were infected with clusterin or sh-clusterin lentivirus and the HDMEC-derived conditioned media were used to treat normal human melanocytes. It was found that HDMEC-derived clusterin inhibits melanogenesis through MITF/tyrosinase downregulation. The findings here suggest that HDMECs secrete copious amounts of clusterin and that the clusterin is a factor contributing to the inhibitory effect of endothelial cells on melanogenesis via paracrine crosstalk between endothelial cells and melanocytes.

Exciton dynamics in heterojunction thin-film devices based on exciplex-sensitized triplet-triplet annihilation.

Exciton dynamics in a solid-state exciplex sensitized triplet-triplet annihilation (ESTTA) system are studied using transient photoluminescence (TrPL) measurements. The ESTTA system is a trilayer structure with 4,4',4''-tris(N-3-methyphenyl-N-phenyl-amino)triphenylamine (m-MTDATA) acting as the electron donor, 1-(2,5-dimethyl-4-(1-pyrenyl)phenyl)pyrene (DMPPP) as a triplet-diffusion-singlet-blocking (TDSB) layer, and 9,10-bis(2'-naphthyl) anthracene (ADN), acting as the electron acceptor and emitter. The thicknesses of the m-MTDATA and ADN layers are 30 nm, while the thickness of the DMPPP layer is varied to characterize its effect on the singlet quenching of the ADN emission. We find that electron transfer via tunneling through the DMPPP layer is the dominant quenching channel, with a characteristic length of ∼5 nm. Doping the high photoluminescence quantum yield molecule 4,4'-bis[2-(4-(N,N-diphenylamino)phenyl)vinyl]biphenyl (DPAVBi) into the ADN layer enhanced the overall intensity of the ESTTA signal but did not prevent quenching by exciplex formation. The trilayer configuration (m-MTDATA/DMPPP/ADN) can effectively prevent ADN singlets from being quenched by electron transfer and exciplex formation, and a key property of the DMPPP is its tendency to not undergo electron transfer to the ADN.

Modeling of carrier transport in organic light emitting diode with random dopant effects by two-dimensional simulation.

To model the carrier transport in organic light-emitting diodes (OLEDs) with random dopant effects in the emitting layer, two-dimensional simulation was used. By including the Gaussian shape density of states and field-dependent mobility in the Poisson and drift-diffusion solver, the carrier transport, trapping in the dopant state, and radiative recombination were accurately modeled. To examine the model, the current-voltage characteristics of organic light-emitting devices were compared. The host material in the emitting layer was 2,2-bis(1-phenyl-1H-benzo[d]imidazol-2-yl)biphenyl (BImBP), which was doped with bis[2-(4,6-difluorophenyl)pyridinato-C2,N](picolinato)iridium(III) (FIrpic) at various concentrations. By including the random doping model, the trend of mobility was altered and the radiative efficiency fitted experimental values well.

High k nanophase zinc oxide on biomimetic silicon nanotip array as supercapacitors.

A 3D trenched-structure metal-insulator-metal (MIM) nanocapacitor array with an ultrahigh equivalent planar capacitance (EPC) of ~300 µF cm(-2) is demonstrated. Zinc oxide (ZnO) and aluminum oxide (Al2O3) bilayer dielectric is deposited on 1 µm high biomimetic silicon nanotip (SiNT) substrate using the atomic layer deposition method. The large EPC is achieved by utilizing the large surface area of the densely packed SiNT (!5 × 10(10) cm(-2)) coated conformally with an ultrahigh dielectric constant of ZnO. The EPC value is 30 times higher than those previously reported in metal-insulator-metal or metal-insulator-semiconductor nanocapacitors using similar porosity dimensions of the support materials.

Application of machine learning algorithms for accurate determination of bilirubin level on in vitro engineered tissue phantom images.

Neonatal Jaundice is a common occurrence in neonates. High excess bilirubin would lead to hyperbilirubinemia, leading to irreversible adverse damage such as kernicterus. Therefore, it is necessary and important to monitor neonates' bilirubin levels in real-time for immediate intervention. However, current screening protocols have their inherent limitations, necessitating more convenient measurements. In this proof-of-concept study, we evaluated the feasibility of using machine learning for the screening of hyperbilirubinemia in neonates from smartphone-acquired photographs. Different machine learning models were compared and evaluated to gain a better understanding of feature selection and model performance in bilirubin determination. An in vitro study was conducted with a bilirubin-containing tissue phantom to identify potential biological and environmental confounding factors. The findings of this study present a systematic characterization of the confounding effect of various factors through separate parametric tests. These tests uncover potential techniques in image pre-processing, highlighting important biological features (light scattering property and skin thickness) and external features (ISO, lighting conditions and white balance), which together contribute to robust model approaches for accurately determining bilirubin concentrations. By obtaining an accuracy of 0.848 in classification and 0.812 in regression, these findings indicate strong potential in aiding in the design of clinical studies using patient-derived images.

Organic-based plasmonic emitters for sensing applications.

Plasmonic emissions generated by excitation of an organic layer on a metal grating structure are demonstrated. The emissions correspond to the resonant condition of surface plasmon (SP) modes on the Alq(3)/Au interface, and the grating structure is coupled to the Au/air interface to provide light emissions. Experimental variations in pitch to control plasmonic bandgap obtained highly directional plasmonic emissions with enhanced intensity. This method is readily applicable for detecting refractive index changes by using SP-coupled fluorophores to obtain emissions of varying wavelengths and viewing angles. The calculations showed that the wavelength of the plasmonic emitter changed from 480 to 680 nm at certain viewing angles, while the concentration of contacting glucose increased from 10% to 40%. Accordingly, a device with a pitch size of 500 nm had a sensitivity of Δθe/Δn=37.76° and Δn/Δ=1.681×10(-4) RIU (refractive index unit). Therefore, the proposed approach has potential applications in low-cost, disposable, point-of-care biosensors.

Risk factors associated with outcomes of very low birthweight infants in four Asian countries.

AIM: The study aims to determine the risk factors associated with mortality and necrotising enterocolitis (NEC) among very low birthweight infants in 95 neonatal intensive care units in the Asian Network on Maternal and Newborn Health. METHODS: This is a cross-sectional study using an international collaborative database of 17,595 very low birthweight infants admitted within 28 days of birth between 2003 and 2006 in four Asian countries. Information on the mortality and morbidity of neonates admitted to the neonatal intensive care units was recorded. Factors associated with the death and diseases of infants were estimated using multilevel multivariate logistic regression. Random effects were included to account for the clustering of the observations. RESULTS: Overall discharge mortality was 15% and it was significantly different by countries and units. The mortality rate was found to be significantly higher in neonates with pulmonary haemorrhage (odds ratio 1.83, 95% confidence interval 1.63-2.04) and air leak syndrome (odds ratio 1.51, 95% confidence interval 1.30-1.72). The incidence of NEC was 4.3% and was strongly associated with other morbidities. Multivariate logistic regression showed that patent ductus arteriosus was the most significant risk factor associated with NEC. CONCLUSIONS: Our analysis has highlighted the great potential that multi-country, collaborative datasets have in terms of epidemiologic research when it comes to identifying issues in perinatal health that are common throughout Asia, and in relation to particular issues pertaining to specific countries and neonatal units. Establishing collaborative networks, conducting analyses of common datasets and further epidemiologic research are now essential measures to improve newborn health in Asia.

The one-step fabrication of porous hASC-laden GelMa constructs using a handheld printing system.

The fabrication of highly porous cell-loaded structures in tissue engineering applications has been a challenging issue because non-porous cell-laden struts can cause severe cell necrosis in the middle region owing to poor transport of nutrients and oxygen. In this study, we propose a versatile handheld 3D printer for the effective fabrication of porous cell-laden methacrylated gelatin (GelMa) with high porosity (≈97%) by air injection and a bubble-making system using mesh filters through which a mixture of air/GelMa bioink is passed. In particular, the pore size and foamability of the cell constructs could be manipulated using various processing parameters (rheological properties of GelMa, filter size and number, and air-bioink volume ratio). To demonstrate the feasibility of the cell construct as a tissue engineering substitute for muscle regeneration, in vitro cellular activities and in vivo regeneration ability of human adipose stem cells were assessed. The in vitro results demonstrated that the human adipose stem cells (hASCs) fabricated using the handheld 3D printer were alive and well-proliferated. Furthermore, the in vivo results showed that the hASCs-constructs directly printed from the handheld 3D printer showed significant restoration of functionality and efficient muscle regeneration in the volumetric muscle loss model of mice. Based on these results, the fabrication method of the porous cell-laden construct could be a promising tool for regenerating muscle tissues.

Birth anthropometry among three Asian racial groups in Singapore: proposed new growth charts.

OBJECTIVE: We analysed birth anthropometry of babies of Chinese, Malay and Indian ancestry living in Singapore with an aim to develop gestational age (GA) and gender-specific birth anthropometry charts and compare these with the widely used Fenton charts. DESIGN: Retrospective observational study. SETTING: Department of Neonatology, National University Hospital, Singapore. POPULATION: We report data from 52 220 infants, born between 1991-1997 and 2010-2017 in Singapore. METHODS: Anthropometry charts were built using smoothened centile curves and compared with Fenton's using binomial test. Birth weight (BW), crown-heel length and head circumference (HC) were each modelled with maternal exposures using general additive model. MAIN OUTCOME MEASURES: BW, crown-heel length and HC. RESULTS: There were 22 248 Chinese (43%), 16 006 Malay (31%) and 8543 Indian (16%) babies. Mean BW was 3103 g (95% CI 3096 to 3109), 3075 g (95% CI 3067 to 3083) and 3052 g (95% CI 3041 to 3062) for Chinese, Malays and Indians, respectively. When exposed to a uniform socioeconomic environment, intrauterine growth and birth anthropometry of studied races were almost identical. From our GA-specific anthropometric charts until about late prematurity, Asian growth curves mirrored that of Fenton's; thereafter, Asian babies showed a reduction in growth velocity. CONCLUSIONS: These findings suggest that Asian babies living in relatively uniform socioeconomic strata exhibit similar growth patterns. There is a slowing of growth among Asian babies towards term, prompting review of existing birth anthropometry charts. The proposed charts will increase accuracy of identification of true fetal growth restriction as well as true postnatal growth failure in preterm infants when applied to the appropriate population.

Shape-memory collagen scaffold combined with hyaluronic acid for repairing intervertebral disc.

BACKGROUND: Intervertebral disc degeneration (IVDD) is a common cause of chronic low back pain (LBP) and a socioeconomic burden worldwide. Conservative therapies and surgical treatments provide only symptomatic pain relief without promoting intervertebral disc (IVD) regeneration. Therefore, the clinical demand for disc regenerative therapies for disc repair is high. METHODS: In this study, we used a rat tail nucleotomy model to develop mechanically stable collagen-cryogel and fibrillated collagen with shape-memory for use in minimally invasive surgery for effective treatment of IVDD. The collagen was loaded with hyaluronic acid (HA) into a rat tail nucleotomy model. RESULTS: The shape-memory collagen structures exhibited outstanding chondrogenic activities, having completely similar physical properties to those of a typical shape-memory alginate construct in terms of water absorption, compressive properties, and shape-memorability behavior. The treatment of rat tail nucleotomy model with shape-memory collagen-cryogel/HA alleviated mechanical allodynia, maintained a higher concentration of water content, and preserved the disc structure by restoring the matrix proteins. CONCLUSION: According to these results, the collagen-based structure could effectively repair and maintain the IVD matrix better than the controls, including HA only and shape-memory alginate with HA.

Power Efficiency Enhancement of Organic Light-Emitting Diodes Due to the Favorable Horizontal Orientation of a Naphthyridine-Based Thermally Activated Delayed Fluorescence Luminophore.

Four emitters based on the naphthyridine acceptor moiety and various donor units exhibiting thermally activated delayed fluorescence (TADF) were designed and synthesized. The emitters exhibited excellent TADF properties with a small ΔE ST and a high photoluminescence quantum yield. A green TADF organic light-emitting diode based on 10-(4-(1,8-naphthyridin-2-yl)phenyl)-10H-phenothiazine exhibited a maximum external quantum efficiency of 16.4% with Commission Internationale de L'éclairage coordinates of (0.368, 0.569) as well as a high current and power efficiency of 58.6 cd/A and 57.1 lm/W, respectively. The supreme power efficiency is a record-high value among the reported values of devices with naphthyridine-based emitters. This results from its high photoluminescence quantum yield, efficient TADF, and horizontal molecular orientation. The molecular orientations of the films of the host and the host doped with the naphthyridine emitter were explored by angle-dependent photoluminescence and grazing-incidence small-angle X-ray scattering (GIWAXS). The orientation order parameters (ΘADPL) were found to be 0.37, 0.45, 0.62, and 0.74 for the naphthyridine dopants with dimethylacridan, carbazole, phenoxazine, and phenothiazine donor moieties, respectively. These results were also proven by GIWAXS measurement. The derivative of naphthyridine and phenothiazine was shown to be more flexible to align with the host and to show the favorable horizontal molecular orientation and crystalline domain size, benefiting the outcoupling efficiency and contributing to the device efficiency.

Trends in neonatal mortality and morbidity in very-low-birth-weight (VLBW) infants over a decade: Singapore national cohort study.

BACKGROUND: Very preterm infants are at risk for neurodevelopmental impairment because of postnatal morbidities. This study aims to (1) compare the outcomes of very-low-birth-weight (VLBW) infants in Singapore during two time periods over a decade; 2) compare performances among Singaporean neonatal intensive care units (NICUs); and 3) compare a Singapore national cohort with one from the Australian and New Zealand Neonatal Network (ANZNN). METHODS: Singapore national data on VLBW infants born during two periods, 2007-2008 (SG2007, n = 286) and 2015-2017 (SG2017, n = 905) were extracted from patient medical records. The care practices and clinical outcomes among three Singapore NICUs were compared using SG2017 data. Third, using data from the ANZNN2017 annual report, infants with gestational age (GA) ≤29 weeks in SG2017 were compared with their Oceania counterparts. RESULTS: SG2017 had 9.9% higher usage of antenatal steroids (p < 0.001), 8% better survival for infants ≤26 weeks (p = 0.174), and used 12.7% lesser nonsteroidal anti-inflammatory drugs for patent ductus arteriosus closure (p < 0.001) than those of SG2007 cohort. Rate of late-onset sepsis (LOS) was almost halved (7.4% vs. 14.0%, p < 0.001), and exclusive human milk feeding after discharge increased threefold (p < 0.001). SG2017, in contrast, had a higher rate of chronic lung disease (CLD) (20.0% vs. 15.1%, p = 0.098). Within SG2017, the rates of LOS, CLD, and human milk feeding varied significantly between the three NICUs. When compared with ANZNN2017, SG2017 had significantly lower rates of LOS for infants ≤25 weeks (p = 0.001), less necrotizing enterocolitis for infants ≤27 weeks (p = 0.002), and less CLD across all GA groups. CONCLUSION: Postnatal morbidities and survival rates for VLBW infants in Singapore have improved over a decade. Outcomes for VLBW infants varied among three Singapore NICUs, which provide a rationale for collaboration to improve clinical quality. The outcomes of Singaporean VLBW infants were comparable to those of their ANZNN counterparts.

Engineering the Macrocyclic Donor Structures towards Deep-Blue Thermally Activated Delayed Fluorescence Emitters.

Deep-blue thermally activated delayed fluorescence (TADF) molecules present promising potential in organic light-emitting diodes (OLEDs), especially for display applications. Here, an efficient molecular engineering approach to modifying the donor or acceptor features of the D-π-A-configured TADF molecules for deep-blue emission is reported. By introducing oxygen and sulfone as a bridge unit onto the macrocyclic donor, two emitters, c-ON-MeTRZ and c-NS-MeTRZ, are synthesized and characterized, respectively. The reduced donor strength of c-ON-MeTRZ and c-NS-MeTRZ as compared to that of the model molecule c-NN-MeTRZ leads to blue-shifted emissions with high photoluminescence quantum yields (PLQYs) and retains TADF characters, while the new emitter c-NN-MePym with the most blue-shifted emission only exhibits a pure fluorescent nature because of the electron-accepting feature of pyrimidine that is insufficient for inducing the TADF property. In the presence of macrocyclic donors, these new emitters show high horizontal dipole ratios (Θ// = 85-89%), which are beneficial for improving the light out-coupling efficiency. Deep-blue TADF OLEDs incorporating c-ON-MeTRZ as an emitter doped in the mCPCN host achieves a high maximum external quantum efficiency (EQEmax) of 30.2% together with 1931 Commission Internationale de I'Eclairage (CIE) coordinates of (0.14, 0.13), while the counter device employing c-NS-MeTRZ as a dopant gives EQEmax of 15.4% and CIE coordinates of (0.14, 0.09). The EQEmax of c-ON-MeTRZ- and c-NS-MeTRZ-based devices can be significantly improved to 34.4 and 29.3%, respectively, with a polar host DPEPO, which stabilizes the charge transfer (CT) S1 state to give lower ΔEST for improving the reverse intersystem crossing process. The efficient TADF character, high PLQYs, and high anisotropic emission dipole ratios work together to render the superior electroluminescence (EL) efficiencies. Based on the detailed characterizations of physical properties, theoretical analyses, and comprehensive study on the corresponding devices, a clear structure-property-performance relationship has been successfully established to verify the effective molecular design strategy of modulating the macrocyclic donor characters for efficient deep-blue TADF emitters.

Semi-Transparent, Pixel-Free Upconversion Goggles with Dual Audio-Visual Communication.

The intractable brittleness and opacity of the crystalline semiconductor restrict the prospect of developing low-cost imaging systems. Here, infrared visualization technologies are established with large-area, semi-transparent organic upconversion devices that bring high-resolution invisible images into sight without photolithography. To exploit all photoinduced charge carriers, a monolithic device structure is proposed built on the infrared-selective, single-component charge generation layer of chloroaluminum phthalocyanine (ClAlPc) coupled to two visible light-emitting layers manipulated with unipolar charges. Transient pump-probe spectroscopy reveals that the ClAlPc-based device exhibits an efficient charge dissociation process under forward bias. This process is indicated by the prompt and strong features of electroabsorption screening. Furthermore, by imposing the electric field, the ultrafast excited state dynamic suggests a prolonged charge carrier lifetime from the ClAlPc, which facilitates the charge utilization for upconversion luminance. For the first time, >30% of the infrared photons are utilized without photomultiplication strategies owing to the trivial spectrum overlap between ClAlPc and the emitter. In addition, the device can broadcast the acoustic signal by synchronizing the device frequency with the light source, which enables to operate it in dual audio-visual mode. The work demonstrates the potential of upconversion devices for affordable infrared imaging in wearable electronics.