Low Optical Transparency Research Articles

Optically transparent and very thin structure against electromagnetic pulse (EMP) using metal mesh and saltwater for shielding windows

An electromagnetic pulse (EMP) with high energy can damage electronic equipment instantly within a wide range of thousands of kilometers. Generally, a metal plate placed inside a thick concrete wall is used against an EMP, but it is not suitable for an EMP shielding window, which requires not only strong shielding effectiveness (SE) but also optical transparency (OT). In this paper, we propose a very thin and optically transparent structure with excellent SE for EMP shielding window application. The proposed structure consists of a saltwater layer held between two glass substrates and two metal mesh layers on the outside of the glass, with a total thickness of less than 1.5 cm. The SE and OT of the structure are above 80 dB and 45%, respectively, which not only meet the requirement of EMP shielding for military purposes but also retain the procedure of good observation. Moreover, the OT of the structure can be significantly improved using only one metal mesh film (MMF) layer, while the SE is still maintained high to satisfy the required SE for home applicants. With the major advantages of low cost, optical transparency, strong SE, and flexible performance, the proposed structure can be considered a good solution for transparent EMP shielding windows.

Manipulation of Zinc Oxide with Zirconium Doping for Efficient Inverted Organic Solar Cells.

Solution-processed zinc oxide (ZnO) is one of the widely used electron transporting layers (ETLs) for organic solar cells (OSCs). However, low optical transparency along with thickness-sensitivity of ZnO ETL constrains the improvement of photovoltaic performance and large-scale fabrication compatibility. To resolve these issues, zirconium (Zr) doping is applied to tailor the optoelectronic and morphological properties of ZnO layer. This approach not only improves light transmittance with the suppressed parasitic absorption, but also provides an optimized surface morphology for enhancing charge extraction property and reducing potential of charge trap-assisted recombination. By using ZnO:Zr as ETL in inverted device configuration, the maximum power conversion efficiency (PCE) of PM6:Y6:PC71 BM solar cell devices is up to 17.2%, which makes an enhancement of 9.55% compared to ZnO-based devices (15.7%). As the thickness of ZnO:Zr ETL increases to ≈60nm, the presence of the lower parasitic absorption together with uniform surface morphology can help photovoltaic performance maintain above 15%, which is beyond the performance of the pristine ZnO-based device achieving only 11.9%. Such superiority of ZnO:Zr ETL is also validated by a series of well-known BHJ systems, where in comparison with the devices based on pristine ZnO ETL, a better photovoltaic performance from ZnO:Zr device can be achieved.

Effects of Tantalum Doping on Electrical Characteristics of Indium-Gallium-Zinc Oxide Thin-Film Transistors

Thin-film transistors (TFTs) that utilize oxide semiconductors as channel materials have been widely used in various electronic device applications, such as displays, sensors, and memory devices. Among the oxide semiconductors, transparent amorphous indium-gallium-zinc oxides (a-IGZO) have superior characteristics, namely, high field-effect mobility (~10cm2/Vs), good uniformity, low processing temperatures, optical transparency, and low-cost fabrication processability compared with conventional amorphous/poly-silicon TFTs. However, oxide TFTs including a-IGZO TFTs have bias stress-induced instabilities, which are still critical issues in launching commercial oxide TFT products. These issues can be attributed to the oxygen vacancy-related defects, which are known to act as a major source of electrons and as carrier traps. To suppress such oxygen vacancy-related defects, many researchers reported various techniques, such as ozone treatment, oxygen annealing on oxide TFTs, passivation, and metal-doped oxide semiconductors.In this study, we investigated the device performance of tantalum (Ta)-doped IGZO TFTs as a function of Ta content. Ta was used as a dopant because of its bond-dissociation-energy (BDE, 805kJ/mol) with oxygen higher than those of In, Ga, and Zn. The Ta-doped IGZO, which was adopted as a channel layer of bottom-gate TFTs, was fabricated using a magnetron co-sputtering method. Heavily doped p-type Si wafer with thermally grown SiO2 (300nm) was used as substrates. The RF power for the a-IGZO (In2O3 :Ga2O3 : ZnO = 1:1:1)target was fixed at 100 W while the power for the Ta target increased from 0 to 50 W. Aluminum (Al) was deposited as source/drain electrodes using an electron beam evaporator. With increasing Ta content in the IGZO films, the field-effect mobility (μFE) of the Ta-doped IGZO TFTs decreased, the threshold voltage (Vth) increased from negative to positive values, and the subthreshold swing (SS) became smaller with higher on/off ratio. Especially, Ta (10W)-doped IGZO TFTs exhibited μFE of 7.11 cm2/Vs, a SS of 0.195V/decade, and an on/off ratio ~1x108. These results show that the Ta-doping improves the switching characteristics of the Ta-IGZO TFTs. Furthermore, to evaluate the bias-stress stability, positive bias stress (PBS), negative bias stress (NBS) tests were conducted.

Increasing the transparency of compact flexible antennas using defected ground structure for unobtrusive wearable technologies

In this paper, new designs of optically transparent wearable antennas have been presented. The explored antennas have the excellent features of high flexibility, small size, low specific absorption rate (SAR) and high optical transparency. The proposed antennas are realised by utilising highly flexible, optically transparent and low-cost materials. For achieving compactness in antenna dimension and for improved transparency, square-ring-shaped radiator is used in the antenna design. To improve the efficiency and gain of the square-ring patch antennas, a new technique is proposed in this paper. The proposed technique utilises a strip line that connects the middle of the two opposite sides of the ring. Full ground plane is used in antenna design to reduce the back radiation. However, full ground plane reduces optical transparency. To elevate optical transparency without affecting antenna's back radiation significantly, a new technique of defected ground structure is investigated in this study. With this defected ground structure, the optical transparency is improved by about 6% without significantly compromising the SAR. The compatibility of the proposed antennas for wearable applications are investigated by examining the performances on flat and bent phantoms. Moreover, the robustness of the antennas are studied by subjecting the prototypes to multiple bending operations.

Design strategy and interface chemistry of ageing stable AZO films as high quality transparent conducting oxide

In this work, an attempt has been made to produce high quality Al-doped ZnO (AZO) transparent conductors by pulsed direct current (DC) magnetron sputtering under varied process conditions, namely sputtering power, sputtering pressure, doping level, and deposition time. The idea is to develop stable AZO films with excellent electro-optical properties, which can replace indium tin oxide (ITO) as transparent conducting oxide. The films are deposited on glass and polyethylene terephthalate (PET) substrates and characterized by X-ray diffraction (XRD), Raman spectroscopy, field emission scanning electron microscopy (FESEM), and energy dispersive X-ray spectroscopy (EDS) for material properties. The electronic and optical properties are investigated using UV–Vis-NIR absorption spectroscopy, photoluminescence spectroscopy, four probe resistivity and Hall measurements, which facilitate the design strategy to achieve promising electro-optical properties. AZO films under optimized process conditions possess sheet resistance below 5 Ω/sq. and maximum visible light transmittance close to 90%. The lowest value of electrical resistivity is found to be 2.1 × 10−4 Ω·cm. The combination of low electrical resistivity and high optical transparency leading to the figure of merit of the order of 10−2 Ω−1 is critically dependent on the process conditions of sputtering as well as doping contents. High free carrier concentration in AZO films leads to the Burstein-Moss shift and this observed blue shift of the absorption spectrum as compared to that of ZnO with native defects depends on the doping contents and the process conditions. This work further explores the role of interface chemistry to achieve high stability of AZO films under ambient oxidizing conditions. The adsorption kinetics of cationic rhodamine 6G and anionic methyl orange at AZO surface with varying adsorption sites and ageing studies on the sheet resistance reveal that the excellent stability of AZO films is delicately linked to the process conditions as well as the content of the dopant material used in the preparation of the AZO sputtering targets. The findings of the study confirm that the sheet resistances of selective AZO films undergo no change and fixed at 4.5 Ω/sq. even for ageing period of over six months.

A live imaging-friendly slice culture method using collagen membranes.

AimOrganotypic brain slice culture preserves the geographical position of neurons and neuronal circuits. The slice cultures also maintain both non‐neuronal cell types and the surrounding extracellular matrix. The interface method has been widely used for slice cultures, in which brain slices are placed on semiporous polytetrafluoroethylene (PTFE) membranes. However, a low optical transparency of PTFE membrane makes it difficult to perform live imaging of deep regions of slice cultures using an inverted microscope. To overcome the issue, we evaluated the suitability of using collagen membranes for slice cultures, especially focusing on live imaging of the cellular dynamics of green fluorescent protein (GFP)‐expressing microglia.MethodsEntorhinohippocampal slices were cultured on either collagen or PTFE membranes. The influence of membrane type on the ability to observe deep regions of slice cultures was examined by live imaging using an inverted microscope.ResultsCollagen membranes were thinner and had better optical transparency compared with PTFE membranes. There were no differences in cell viability, density of neurons or microglia. The densify of visible short branches of microglia in live imaging was higher in collagen membranes than PTFE membranes.ConclusionCollagen membranes are suitable for live imaging of cellular dynamics in slice cultures using an inverted microscope.

Electroplated Silver-Nickel Core-Shell Nanowire Network Electrodes for Highly Efficient Perovskite Nanoparticle Light-Emitting Diodes.

The low sheet resistance and high optical transparency of silver nanowires (AgNWs) make them a promising candidate for use as the flexible transparent electrode of light-emitting diodes (LEDs). In a perovskite LED (PeLED), however, the AgNW electrode can react with the overlying perovskite material by redox reactions, which limit the electroluminescence efficiency of the PeLED by causing the degradation of and generating defect states in the perovskite material. In this study, we prepared Ag-Ni core-shell NW electrodes using the solution-electroplating technique to realize highly efficient PeLEDs based on colloidal formamidinium lead bromide (FAPbBr3) nanoparticles (NPs). Solvated Ni ions from the NiSO4 source were deposited onto the surface of AgNW networks in three steps: (i) cathodic cleaning, (ii) adsorption of the Ni-ion complex onto the AgNW surface, and (iii) uniform electrodeposition of Ni. An ultrathin (∼3.5 nm) Ni layer was uniformly deposited onto the AgNW surface, which exhibited a sheet resistance of 16.7 Ω/sq and an optical transmittance of 90.2%. The Ag-Ni core-shell NWs not only increased the work function of the AgNW electrode, which facilitated hole injection into the emitting layer, but also suppressed the redox reaction between Ag and FAPbBr3 NPs, which prevented the degradation of the emitting layer and the generation of defect states in it. The resulting PeLEDs based on FAPbBr3 NPs with the Ag-Ni core-shell NWs showed high current efficiency of 44.01 cd/A, power efficiency of 35.45 lm/W, and external quantum efficiency of 9.67%.

Ethanol-Precursor-Mediated Growth and Thermochromic Applications of Highly Conductive Vertically Oriented Graphene on Soda-Lime Glass.

Direct growth of vertically oriented graphene (VG) nanowalls on soda-lime glass has practical significance in extending the application of graphene to daily-life-related areas, such as gas sensors and conductive electrodes, via combining their complementary properties and applications. However, VG films derived by low-temperature deposition (e.g., on glass) usually present relatively low conductivity and optical transparency. To tackle this issue, an ethanol-precursor-based, radio-frequency plasma-enhanced chemical vapor deposition (rf-PECVD) route for the synthesis of VG nanowalls is developed in this research, at around the softening temperature of soda-lime glass (∼600 °C) templates. The average sheet resistance, i.e., ∼2.4 kΩ·sq-1 (at transmittance ∼81.6%), is only one-half of that achieved by a traditional methane-precursor-based PECVD route. Based on the highly conductive and optically transparent VG/glass, as well as its scalable size up to 25 in. scale, high-performance reversible thermochromic devices were successfully constructed using VG/glass as transparent heaters. Hereby, this work should propel the scalable synthesis and applications of highly conductive VG films on glass in next-generation transparent electronics and switchable windows.

The influence of ZnO layer thickness on the performance and electrical bias stress instability in ZnO thin film transistors

Thin Film Transistors (TFTs) are the active elements for future large area electronic applications, in which low cost, low temperature processes and optical transparency are required. Zinc oxide (ZnO) thin film transistors (TFTs) on SiO2/n+-Si substrate are fabricated with the channel thicknesses ranging from 20 nm to 60 nm. It is found that both the performance and gate bias stress related instabilities of the ZnO TFTs fabricated were influenced by the thickness of ZnO active channel layer. The effective mobility was found to improve with increasing ZnO thickness by up to an order in magnitude within the thickness range investigated (20–60 nm). However, thinner films were found to exhibit greater stability in threshold voltage and turn-on voltage shifts with respect to both positive and negative gate bias stress. It was also observed that both the turn on voltage (Von) and the threshold voltage (VT) decrease with increasing channel thickness. Moreover, the variations in subthreshold slope (S) with ZnO thickness as well as variations in VT and Von suggest a possible dependence of trap states in the ZnO on the ZnO thickness. This is further correlated by the dependence of VT and Von instabilities with gate bias stress.

Characterization of CO2 fixation on algal biofilms with an infrared gas analyzer and importance of a space-rich structure on the surface

An attached microalgal culture system, or a biofilm system, which can reduce the cost of biomass recovery, is an attractive approach to solve the CO2 problem. In this study, we developed a method for precisely measuring CO2 fixation on algal biofilms, and optimized the photosynthetic capacity of a unicellular microalga, Chlorella. The CO2 concentration in the sample gas, measured with an infrared gas analyzer, was corrected by considering the difference in H2O concentration between the sample gas and the reference gas. The corrected CO2 concentration coincided with that of the reference gas, for which there were no cells. Using the established method, the photosynthetic capacity of Chlorella attached to a glass fiber membrane filter was characterized. Interestingly, the CO2 fixation rate per chlorophyll was almost the same as in liquid, at cell densities of up to 120 mg chlorophyll m−2. The light-dependency on the filter was very similar to that in liquid, while the photosynthetic rate was more markedly limited under low CO2 conditions than in liquid, suggesting that CO2 is a more severe limiting factor than light on the filter. The cell concentration-dependency of photosynthesis and microscopic observations suggest that photosynthesis is only performed by cells in a few top layers on the filter. To improve the CO2 supply, the solid surface was changed to a towel, which increased the photosynthetic rate in spite of its low optical transparency. The maximum rate of CO2 capture per area was estimated to be over 110 tons ha−1 year−1. These findings suggest that the Chlorella solid-surface culture system is a promising system for carbon capture, and that it can be further improved if the solid surface is converted into a steric structure with a high optical transparency.

Transparent carbon nanotubes promote the outgrowth of enthorino-dentate projections in lesioned organ slice cultures.

The increasing engineering of carbon-based nanomaterials as components of neuroregenerative interfaces is motivated by their dimensional compatibility with subcellular compartments of excitable cells, such as axons and synapses. In neuroscience applications, carbon nanotubes (CNTs) have been used to improve electronic device performance by exploiting their physical properties. Besides, when manufactured to interface neuronal networks formation in vitro, CNT carpets have shown their unique ability to potentiate synaptic networks formation and function. Due to the low optical transparency of CNTs films, further developments of these materials in neural prosthesis fabrication or in implementing interfacing devices to be paired with in vivo imaging or in vitro optogenetic approaches are currently limited. In the present work, we exploit a new method to fabricate CNTs by growing them on a fused silica surface, which results in a transparent CNT-based substrate (tCNTs). We show that tCNTs favor dissociated primary neurons network formation and function, an effect comparable to the one observed for their dark counterparts. We further adopt tCNTs to support the growth of intact or lesioned entorhinal-hippocampal complex organotypic cultures (EHCs). Through immunocytochemistry and electrophysiological field potential recordings, we show here that tCNTs platforms are suitable substrates for the growth of EHCs and we unmask their ability to significantly increase the signal synchronization and fiber sprouting between the cortex and the hippocampus with respect to Controls. tCNTs transparency and ability to enhance recovery of lesioned brain cultures, make them optimal candidates to implement implantable devices in regenerative medicine and tissue engineering.

Bioinspired Metal Mesh Structure with Significant Electrical and Optical Properties

Abstract1D metal network is one of the promising alternatives of the conventional transparent conducting electrode (TCE) viz ITO/FTO. Bioinspired fabrication of junction resistance free metal grid structures is explored for their TCE applications. The leaf‐based metal grid electrodes exhibit low DC resistivity (10−5–10−4 Ω cm) and high optical transparency (80–90%) in the visible spectrum. The leaf vein structures are varied to obtain better optoelectronic properties. Finally, a multilayered stacked structure (SnO2‐Ag‐Au‐SnO2) is deposited on a poly ethyl terephthalate substrate and low‐ to high‐temperature electrical stability is demonstrated. X‐ray photoelectron spectroscopy results are used to investigate the structural study of the leaf‐based 1D structure. A minimal variation in Rs values is seen even after 1000 times bending for the flexible transparent structure. It is demonstrated that the specific leaf vein–based metal structures can attain good optical, electrical, and mechanical performance.

Vapor Deposition of Transparent, p-Type Cuprous Iodide Via a Two-Step Conversion Process

Photovoltaic devices require p-type layers with high optical transparency and electrical conductivity. One promising material is cuprous iodide, CuI, thin films of which have hole mobilities in the 1–12 cm2/V·s range. However, despite adequate electrical properties in many CuI thin films, most deposition processes afford only rough films that have poor continuity and low optical transparency, hampering the final device performance. We now report an all-vapor method, amenable to large-scale processing, for preparation of CuI thin films with near record optical and electrical properties. In this process, thin films of Cu(2–x)S (x = 0–0.1) or Cu2O grown by chemical vapor deposition from bis(N,N′-di-sec-butylacetamidinato)dicopper(I) in combination with hydrogen sulfide or water, respectively, were converted to γ-CuI upon exposure to dilute hydrogen iodide vapor. The rate of this iodide-for-chalcogenide anion exchange reaction is controlled by the concentration and delivery rate of HI. The nucleation rate of ...

An Effect of Plasmonic Welding of Agnws on EAP Actuator

Carbon grease, CNT, graphene, and AgNWs have been generally used as materials of EAP actuator compliant electrode for large displacement. Carbon grease can withstand for large displacement, but has low optical transparency and mechanical stability. Even though CNT, graphene and AgNWs are transparent compared with carbone grease, they should be thickly coated to secure a stable electric conductivity so that compliant electrodes are still opaque and limited to their applications. In order to verify plasmonic welding effect on AgNWs, we chose 1.75μl/cm2 among different AgNWs concentrations due to its high transparency. Glass substrate which is spary coated with 1.75μl/cm2 AgNWs was put into the chamber and irradiated with 500W halogen lamp. After the irradiation with different time, sheet resistance was measured 4 point probe. Sheet resistance does not change too much until 120 sec, 35 Ω/sq, gradually decreases, and has a minimum value of 19 Ω/sq at 180 sec. After then, sheet resistance increases and shows 198 Ω/sq at 240 sec. In order to confirm plasmonic welding effect on deformation of DE actuator exactly, deformation should be measured with the same DE actuator before and after plasmonic welding. In our conventional DE actuator fabrication process, acrylic frames are used to hold DE membrane. However, they are so vulnerable to heat that it can be easily twisted during plasmonic welding. Therefore, DE actuator (diameter of active area : 30mm) was fabricated by conventional fabrication process with perforated glass frame instead of acrylic frame. We measured its displacement with input voltage by Polytec PSV-500 scanning vibrometer before and after plasmonic welding. Concentration of AgNWs is 1.75μl/cm2 and plasmonic welding time was 180sec welding. The displacement of DE actuator before plasmonic welding was 51μm, 143μm, 320μm, 647μm, 1123μm, 1690μm, and 2240μm at 1 KV, 1.5 KV, 2 KV, 2.5 KV, 3 KV, 3.5 KV and 4Kv, respectively. After plasmonic welding, the displacement of DE actuator was 58μm, 159μm, 358μm, 717μm, 1242μm, 1876μm, and 2512μm at 1 KV, 1.5 KV, 2 KV, 2.5 KV, 3 KV, 3.5 KV and 4Kv, respectively. Figure 1

Advanced Functional Materials Solutions to Engineering the Neural Interface

Advanced Functional Materials Solutions to Engineering the Neural Interface

Enhancement of structure stability and luminescence intensity of LiYF4:Ln3+ nanocrystals

LiYF4 nanocrystals with tetragonal structure were adopted as the host materials for the phosphors and scintillators owing to the low phonon energy and high optical transparency. LiYF4:Ln3+(Ce3+,Eu3+) nanocrystals were fabricated by solvothermal method. Under UV excitation, they could emit visible light. In order to improve the luminescence intensity, the method of co-doping LiYF4 nanocrystals with Sc was adopted. Sc3+ ions could reduce the lattice expansion caused by the doping of Ce3+ or Eu3+ whose ionic radius was larger than Y3+. Crystal structure of Li(Y,Sc)F4:Ln3+ kept much more stable and the luminescence intensity could be significantly enhanced when the concentration of Sc was a moderate value. Thermoluminescence was employed to analyze the electron traps in Li(Y,Sc)F4:Ce3+. Results suggested that the suppression of the generation of electron traps with the co-doping of Sc contributed to the enhancement of luminescence intensity of LiYF4:Ce3+.

“Negative” gap in the spectrum of localized states of (In2O3)0.9(SrO)0.1

The reflection R(ħω), transmission t(ħω), absorption α(ħω), and refraction n(ħω) spectra of polycrystalline In2O3–SrO samples with low optical transparency, which contain In2O3 and In2SrO4 crystallites with In4SrO6 + δ interlayers, are examined. In the region of small ħω values, the reflection coefficient decreases as the resistance of samples saturated with oxygen increases. Spectral dependences n(ħω) and α(ħω) are calculated using the classical electrodynamics relations. The results are compared to the data based on the t(ħω) spectra. The calculated absorption spectra are interpreted within the model with an overlap of tails of the density of states in the valence band and in the conduction band. A “negative” gap E gn in the density of states with a width from–0.12 to–0.47 eV is formed in highly disordered samples in this model. It is demonstrated that the high density of defects and the band of deep acceptor states of strontium in the major matrix In2O3 phase are crucial to tailing of the absorption edge and its shift toward lower energies. The direct gap E gd = 1.3 eV corresponding to the In2SrO4 phase is determined. The energy band diagram and the contribution of tunneling, which reduces the threshold energy for interband optical transitions, are discussed.

Fabrication and optimization of transparent conductive films using laser annealing and picosecond laser patterning

In this article, we propose a systematic method of optimizing the properties of transparent conductive films that possess high electrical conductivity and low optical transparency, by using laser patterning and doping. Prediction maps were constructed, which show the effects of patterning and doping for all possible combinations of initial film conditions (in terms of sheet resistance and transparency) and the degrees of patterning. Using these maps, the properties of transparent conductive films can be easily optimized. We first fabricated graphene-based transparent conductive films on fused silica glass by laser annealing of diamond-like carbon films, and then picosecond laser patterning and doping were successively conducted employing the processing conditions suggested by the maps. For patterning, two types of patterns, circular and square, were considered and prediction maps were separately constructed for both patterns. In this study, a film originally having a sheet resistance of 578Ω/sq and a transparency of 25% was transformed to a 2823Ω/sq and 80.6% film when 73% of the film was removed using square patterns and doped by nitric acid. Experimental data agreed well with predicted values.

Nanoplasmonic Sensing at the Carbon-Bio Interface: Study of Protein Adsorption at Graphitic and Hydrogenated Carbon Surfaces.

Various forms of carbon are known to perform well as biomaterials in a variety of applications and an improved understanding of their interactions with biomolecules, cells, and tissues is of interest for improving and tailoring their performance. Nanoplasmonic sensing (NPS) has emerged as a powerful technique for studying the thermodynamics and kinetics of interfacial reactions. In this work, the in situ adsorption of two proteins, bovine serum albumin and fibrinogen, were studied at carbon surfaces with differing chemical and optical properties using nanoplasmonic sensors. The carbon material was deposited as a thin film onto NPS surfaces consisting of 100 nm Au nanodisks with a localized plasmon absorption peak in the visible region. Carbon films were fully characterized by X-ray photoelectron spectroscopy, atomic force microscopy, and spectroscopic ellipsometry. Two types of material were investigated: amorphous carbon (a-C), with high graphitic content and high optical absorptivity, and hydrogenated amorphous carbon (a-C:H), with low graphitic content and high optical transparency. The optical response of the Au/carbon NPS elements was modeled using the finite difference time domain (FDTD) method, yielding simulated analytical sensitivities that compare well with those observed experimentally at the two carbon surfaces. Protein adsorption was investigated on a-C and a-C:H, and the protein layer thicknesses were obtained from FDTD simulations of the expected response, yielding values in the 1.8-3.3 nm range. A comparison of the results at a-C and a-C:H indicates that in both cases fibrinogen layers are thicker than those formed by albumin by up to 80%.

Influence of structure 3,5,7,3′,4′–Pentahydroxyflavone-based polymer films on their optical transparency

Optical properties and morphology of polymer films based on diglycidyl ether of bis-phenol A and on natural compound 3,5,7,3′,4′–pentahydroxyflavone (quercetin) using UV–vis spectroscopy, scanning electron microscopy and powder X-ray diffraction methods have been investigated. The influence of ordering degree of the polymers, flexibility of their chains, intensity of intermolecular interaction between the quercetine moieties on the polymers' morphology was discussed.It is shown that all the quercetine-based polymer films are transparent at visible and near infrared regions beginning from 420 to 450 nm. Low optical transparency in the short-wavelength region can be explained the self-absorption of quercetin moieties in the polymer chains.