Narrow Absorption Band Research Articles

A bi-directional metamaterial perfect absorber based on gold grating and TiO2-InAs normal hexagonal pattern film

We present and study a bidirectional metamaterial-perfect absorber based on TiO2-InAs regular hexagonal pattern thin films and gold grating. We employ the finite difference time domain approach for simulation. Multi-narrowband perfect absorption and ultra-wideband perfect absorption can alternate as the light source's direction changes. Four narrow-band absorption peaks developed at 987 nm, 1188 nm, 1510 nm, and 2091 nm, respectively, when the incident light struck the bottom. The corresponding absorption efficiencies were 99.69 %, 99.41 %, 98.54 %, and 98.97 %. The broadband region displays the properties of perfect absorption when incident light strikes the top. It should be noted that it is not affected by the polarization or angle of the incidence. With an average absorption efficiency of 96.02 %, the structure attains over 90 % absorption in the 3023 nm range (424–3447 nm). Second, the weighted absorption efficiency of the full spectrum is as high as 96.84 %, and the AM 1.5 solar radiation spectrum and the solar absorption spectrum are strongly coincident. Furthermore, the computation results show that the thermal radiation efficiency is greater than 95 % between 300 K and 1500 K. The electric field distribution revealed that the Fabry-Perot cavity resonance within the film, the surface plasmon resonance (SPR) on the surface of the InAs and TiO2 regular hexagonal pattern films, the interstitial mode excitation between the films, and the excitation cavity coupling between cells of each unit were primarily responsible for the perfect absorption of broadband. The high-order resonant coupling in the FP cavity and the strong coupling between the local surface plasmon resonance and the FP cavity resonance in the metal grating's slit are the primary causes of the narrow band's perfect absorption. The suggested bidirectional metamaterial perfect absorber has significant promise for use in the disciplines of sensing, solar energy absorption, photoelectric detection, and photothermal conversion, as evidenced by its superb absorption and thermal radiation characteristics.

A Novel Frequency-Selective Surface-Enhanced Composite Honeycomb Absorber with Excellent Microwave Absorption

Multifunctional structures with excellent wave-absorbing and load-bearing properties have attracted much attention in recent years. Unlike other wave-absorbing materials, honeycomb wave-absorbing materials have appealing radar absorption and mechanical properties. However, the existing honeycomb wave-absorbing materials have problems such as narrow absorption band and poor compression resistance. In this study, a novel frequency selective surface-enhanced composite honeycomb absorbers (FSS-CHAs) are fabricated by combining a honeycomb structure with wonderful load-bearing capacity and FSS through screen-printing and inlay-locking techniques. After reflectivity measurements, the effective absorption band (RL < −10 dB) of CHA is 6.25–17.47 GHz and a bandwidth of 11.22 GHz, the effective absorption band of the FSS-CHA is 3.96–18 GHz and a bandwidth of 14.04 GHz, 25.13% improvement compared to the CHA, the mechanism of wave absorption is explained using transmission line theory. The simulation results show that the wide bandwidth is due to the different absorption mechanisms of FSS-CHA at low and high frequencies. The compression test shows that the compression strength of FSS-CHA is 17.10 MPa. In addition, FSS-CHA has a low cost of only USD 270.7/m2. This study confirms the possibility of combining FSS with radar-absorbing honeycombs, which provides a reference for the design of future broadband wave-absorbing structures, offers a novel approach to integrating FSS with CHA, and aims to optimize their efficacy and utility in stealth technology.

The Influence of Temperature and Stoichiometry on the Optical Properties of CdSe Nanoplatelets.

Colloidal quasi-two-dimensional cadmium chalcogenide nanoplatelets have attracted considerable interest due to their narrow excitonic emission and absorption bands, making them promising candidates for advanced optical applications. In this study, the synthesis of quasi-two-dimensional CdSe NPLs with a thickness of 3.5 monolayers was investigated to understand the effects of synthesis temperature on their stoichiometry, morphology, and optical properties. The NPLs were synthesized using a colloidal method with temperatures ranging from 170 °C to 210 °C and optimized precursor ratios. Total reflection X-ray fluorescence (TXRF) analysis was employed to determine stoichiometry, while high-resolution transmission electron microscopy (HRTEM) and UV-Vis spectroscopy and photoluminescence spectroscopy were used to analyze the structural and optical characteristics. The results showed a strong correlation between increasing synthesis temperature and the enlargement of nanoscroll diameters, indicating dynamic growth. The best results in terms of uniformity, stoichiometry, and optical properties were achieved at a growth temperature of 200 °C. At this temperature, no additional optical bands associated with secondary populations or hetero-confinement were observed, indicating the high purity of the sample. Samples synthesized at lower temperatures exhibited deviations in stoichiometry and optical performance, suggesting the presence of residual organic compounds.

THz biosensing for early detection of influenza and coronaviruses using dielectric metamaterials

Abstract The world has faced a significant challenge since December 2019, when coronavirus (COVID-19) was found. Viruses of this type are causing pandemics all over the world right now. For this purpose, a biosensor is designed to operate based on metamaterial (MM) incorporated and can detect different coronaviruses. The proposed metamaterial absorber (MMA) includes two bands with perfect absorption characteristics and a narrow absorption bandwidth: 4.093 THz and 3.647 THz. The circuit model’s transmission line technique is another approach to verifying the absorber’s functionality. The proposed design consists of a square-shaped graphene ring (SGR) and a silicon-based square ring resonator (SSRR) to provide unique and narrow band absorption characteristics. Changing the graphene’s chemical potential suggests MMA tuneability and control capability. The suggested MMA can detect several coronaviruses because of its extremely narrow absorption spectrum behavior. It has unique features such as ultra-narrow absorption bandwidth, polarization insensitivity, and simplicity. The MMA is designed with a compact structure, good sensitivity (s), exceptional figure of Merit (FOM), and superior Quality factor (Q) values.

Single-layer black phosphorus-enhanced narrowband perfect absorber in the terahertz range

In this paper, a narrowband absorber based on black phosphorus (BP) is proposed. By utilizing a single-layer BP, a Si structure with four etched holes, and a perfectly electrically conductive (PEC) plate, multi-band absorption can be achieved in the range of 3.8 THz to 5.0 THz. The location and absorbance of the three peaks are 4.32 THz (99.7 %), 4.53 THz (95.6 %), and 4.69 THz (56.7 %), respectively. The anisotropy of the BP structure leads to different absorption spectra when illuminated by TE and TM polarized light sources. Altering the electron doping in BP allows control over the position and intensity of absorption peaks. Upon examining the electric field distribution of the absorber, it is evident that the dominant physical mechanism is the localized surface plasmon resonance (LSPR). Overall, the monolayer BP absorber designed in this study can be utilized to construct a polarimetric sensor for infrared wavelengths. Additionally, it provides a valuable reference for 2D anisotropic plasma devices.

Multifunctional ANF/ CNT/FCIP aerogels with superior sound and electromagnetic wave absorption and mechanical properties

Aerogels exhibit bright prospect for multifunctional applications in noise reduction, radar stealth, load bearing, etc. Existing aerogels however suffer from poor sound absorption at low frequencies, narrow-band electromagnetic wave absorption and low structural strength. Here, we propose a novel lightweight aerogel composed of aromatic polyamide nanofiber (ANF)/ carbon nanotubes (CNT)/ flake carbonyl iron powder (FCIP) to boost acoustic/electromagnetic absorption and mechanical performance simultaneously. The FCIP additives create surface roughness and enlarge the pore size of the aerogel. As a result of the enhanced viscous energy dissipation by surface roughness and better impedance match achieved due to the enlarged pores, sound absorption at low frequency is significantly improved. Besides, the electrically and magnetically conductive network generated by embedded FCIP brings about effective electromagnetic absorption covering the whole X-band. Moreover, the aerogels undergo an increase in skeleton thickness and pore size by FCIP, resulting in maximum compressive stress increment. Our study provides clear guidance for the performance enhancement of aerogels that advances the development of aerogels for multifunctional applications.

Particle swarm optimization of high Q factor interdigitated E-shaped metamaterial for refractive index sensing

Metamaterials for refractive index sensing applications have garnered significant attention in recent years. However, achieving an optimal balance between high sensitivity and quality factor, which together determine the Figure of Merit of sensors, necessitates extensive optimization efforts. In this paper, we present the metaheuristic optimization of a refractive index-based plasmonic sensor operating at a wavelength of 1500 nm, which has the potential to open new avenues for applications in biomedical sensing and beyond. Particle Swarm Optimization is utilized to maximize the performance of the proposed infrared metamaterial sensor. The proposed design features two overlapping E-shaped silver patches placed on top of a grounded Al2O3\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\mathrm {Al_{2}O_{3}}$$\\end{document} substrate. This configuration results in a narrow-band absorption spectrum with peak resonances caused by the confinement of the electric field within the gaps of the E-shaped metallic arms. The metaheuristic optimization process yielded sensor dimensions that achieve a high sensitivity of 834.7 nm/RIU,Q = 865 and a Figure of Merit of 481.34 RIU-1\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\ extrm{RIU}^{-1}$$\\end{document}, demonstrating outstanding performance in cancer cell detection.

Advancing resource sustainability with green photothermal materials: Insights from organic waste-derived and bioderived sources

Abstract Recently, there has been a surge of interest in developing new types of photothermal materials driven by the ongoing demand for efficient energy conversion, environmental concerns, and the need for sustainable solutions. However, many existing photothermal materials face limitations such as high production costs or narrow absorption bands, hindering their widespread application. In response to these challenges, researchers have redirected their focus toward harnessing the untapped potential of organic waste-derived and bioderived materials. These materials, with photothermal properties derived from their intrinsic composition or transformative processes, offer a sustainable and cost-effective alternative. This review provides an extended categorization of organic waste-derived and bioderived materials based on their origin. Additionally, we investigate the mechanisms underlying the photothermal properties of these materials. Key findings highlight their high photothermal efficiency and versatility in applications such as water and energy harvesting, desalination, biomedical applications, deicing, waste treatment, and environmental remediation. Through their versatile utilization, they demonstrate immense potential in fostering sustainability and support the transition toward a greener and more resilient future. The authors’ perspective on the challenges and potentials of platforms based on these materials is also included, highlighting their immense potential for real-world implementation.

Theory and application of temporal coupling mode for a SiC/CaF2/Ag cell-based grating.

Tailoring spectral thermal radiation properties via multiple resonances excited by micro/nanoscale-patterned structures plays a vital role in designing functional emitters and devices. However, predicting thermal radiation properties of a structure with multiple resonances-via a fast and accurate algorithm-is still challenging because of the complex mode coupling effects of different resonances. Herein, we establish a temporal coupling mode (TCM) model for a SiC/CaF2/Ag cell-based grating by extracting the intrinsic parameters and coupling constants of the resonances. The accuracy and efficiency of the established TCM model for predicting absorption spectra of SiC/CaF2/Ag gratings with multiple resonances in each unit cell is verified. Results indicate that the narrowband absorption of the SiC/CaF2/Ag cell-based grating can be enhanced via the multiple-resonance coupling effects. This work provides an alternative tool for predicting absorption characteristics of complex structures with multiple-resonance coupling effects.

Low temperature phase transitions in the visible and near-infrared (VNIR) reflectance spectra of (NH4)2HPO4 and (NH4)HSO4 salts

The detection of ammonium bearing crystalline solids in salt-water systems on icy bodies and solar system bodies could provide information about the ascent of these salts from a deep reservoir within the hydrosphere. Due to their chemical-physical properties, NH4+ compounds play a key role both in the internal dynamics of celestial bodies and in the potential habitability of ocean worlds. In this work we analysed the reflectance spectra of two synthetic NH4+ salts: ammonium hydrogen phosphate (NH4)2HPO4 and ammonium hydrogen sulphate (NH4)HSO4 in the 1–4.2 μm spectral range at low temperature, between 110 and 290 K. For (NH4)2HPO4 we also examined the effect of three different grain sizes (150–125 μm; 125–80 μm; 80–32 μm). The collected reflectance spectra show absorption features related to NH4+ group overtone and combination modes in the 1–2.5 μm range. In particular, the bands located at ∼1.09 μm (3ν3), ∼1.30 μm (2ν3 + ν4), ∼1.58 μm (2ν3), ∼2.02 μm (ν2 + v3) and ∼ 2.2 μm (v3 + v4) could be useful to discriminate these salts. The low temperature spectra, compared to those at ambient temperature, reveal finer structures, displaying sharper and narrower absorption bands. The selected NH4+-bearing salts are subjected to reversible low temperature phase transitions, which are revealed in the spectra by a progressive growth and shift of the bands toward shorter wavelengths with a drastic change of their depth. We performed laboratory measurements of ammonium (NH4+) compounds to address the limited data available expanding the existing database. The collected cryogenic spectra can be directly compared with remote sensing data from planetary missions of the upcoming decade such as NASA's Europa Clipper, and ESA's JUICE and the newly launched James Webb Space Telescope expanding the existing database of ammonium compounds at cryogenic temperature.

Angular- and polarization-insensitive free-standing graphene oxide films for broadband light absorbing applications

Free-standing graphene oxide (FSGO)-based films with angular and polarization insensitivities are demonstrated for broadband absorption applications. The modified Hummers’ method was used to prepare the GO powder. An easily scalable process (evaporation-induced self-assembly) was used to synthesize the FSGO films. The FSGO broadband absorbers with omni-direction and polarization-independent nature was achieved by varying the GO concentrations. The FSGO films were prepared at different GO concentrations to achieve different thicknesses (2–15 μm). The FSGO film with the highest GO concentration (∼10 mg/ml) exhibited high absorptance (α = 0.91) in the broadband region (i.e., 250–2500 nm). The transition from narrow band absorber to a broadband absorber is achieved by varying the GO concentration. The optimized FSGO film (8 mg/ml) shows α of 0.91 with angular and polarization-insensitivity in the visible region. At concentrations <8 mg/ml, the FSGO films are translucent and do not exhibit broadband absorption behavior. Spectroscopic ellipsometry measurements indicate the low refractive index nature of the FSGO films (n = 1.7–1.2 at 400–800 nm). The low refractive index combined with the unique surface morphology of the FSGO films resulted in broadband absorption. Optical simulations were performed to validate the absorption mechanism of the FSGO films.

A three-band narrow-band terahertz perfect absorber for patch antennas and other sensors

We have studied a multi-mode resonance and actively tunable high-sensitivity terahertz perfect absorber using a microstructured Dirac semimetal. The absorber is composed of gold-dielectric-Dirac semimetal three-layer structure, which has good optical sensing characteristics. The absorber produces three perfect absorption modes (>95%) in the range of 2–6 THz, with a minimum bandwidth (FWHM) of 0.18 THz. We studied the adaptability of the device response mode to the actual complex electromagnetic environment by simulating the deflection incident angle. In addition, we also analyzed the influence of various parameter variables on the absorption performance, which provides a clearer idea and more possibilities for the wider application of the device. In terms of sensing detection, the absorber has a maximum refractive index sensitivity S of 610 GHz/RIU and a maximum figure of merit FOM of 3.4 in the ambient refractive index range of 1 to 1.8. Finally, we also realized the tunable absorption frequency of the absorber in 60–80 meV. We believe that based on the good optical properties of the absorber, the device has potential application value in communication technology, space exploration and so on.

Narrow-band absorption enhancement and modulation of single layer graphene by surface plasmon polaritons in near-infrared region

We theoretically study the very sharp absorption enhancement of the single layer graphene by the surface plasmon polaritons in near-infrared region. We place the single layer graphene on the silver substrate surface with a periodic slit array. Such a structure design is helpful to reduce the difficulty in experimental fabrication. By changing the slit period, we can largely tune the absorption peak of the single layer graphene in the wavelength range from 1000 nm to 2000 nm, covering the well-known communication wavelength of 1550 nm. The absorption efficiency of the single layer graphene varies between about 20 % and 80 %, and the absorption bandwidth is reduced from about 10 nm to 1 nm. Moreover, by changing the Fermi energy of the single layer graphene, we can also completely modulate the absorption peak from a maximum to almost zero and thus realize a nearly 100 % modulation depth. This work has a potential application in electro-optic modulators.

Fe3O4/Au@SiO2 nanocomposites with recyclable and wide spectral photo-thermal conversion for a direct absorption solar collector

The Fe3O4-based photothermal materials have been widely applied for the recycling of heavy metal nanoparticles to avoid secondary pollution in the utilization of solar energy owing to excellent magnetic properties. However, the narrow absorption band of Fe3O4 or metal nanoparticles limits their capacity for solar energy harvesting. In this paper, a recyclable and wide spectral photo-thermal conversion system (Fe3O4/Au@SiO2) based on Fe3O4 nanospheres and SiO2-modified Au nanorods (NRs) is prepared. Owing to the strong coupling effect between Fe3O4 and different Au NRs, the wide and strong absorption band from 400 nm to 1100 nm is obtained. Under the influence of magnetic field, the temperature change of nanofluids (NFs) at different positions can be controlled. When the concentration is 0.0467 vol%, the solar energy absorption fraction reaches 96.50 %. Besides, the photothermal performance of Fe3O4/Au@SiO2 NFs at different flow rates is investigated and the results show that temperature rise decreases as increasing flow rate. Finally, a water evaporator device based Fe3O4/Au@SiO2 NFs is developed. The maximum water evaporation rate of 2.6 kg m−2 h−1 can be reached and the movement of evaporator on water can be operated using magnetic field, showing great photothermal conversion performance and recovery potential in practical applications.

A Nanorod With Near-Perfect Absorption for Efficient Utilization of Solar Thermal Energy

Solar thermal utilization faces a significant challenge, with efficient photothermal conversion being the primary issue. Although plasma nanofluid-based direct absorption solar collectors have shown potential in providing excellent sunlight capture capabilities, their narrow-band absorption limits their efficient photothermal conversion. This study proposes an alternative solution by introducing gold nanorods that achieve nearly perfect absorption across 300–1100 nm. The study demonstrates that the spectral absorption capacity of nanorods remains unaffected by their size and material at specific concentrations and depths. The analysis of the electromagnetic distribution at the resonance absorption peak reveals that the nanorods exhibit a “lightning rod” effect and surface plasmon resonance, leading to significant absorption. Additionally, the study investigates the effect of five common plasma nanomaterials on the nanorods’ optical absorption properties. The results show that titanium nitride-based nanorods exhibit broad-spectrum absorption and require only a small concentration and depth to achieve a 95% solar weighted absorption fraction. This research provides a valuable guide for the efficient photothermal conversion of plasma nanofluids, enhancing their potential for solar thermal systems.

Multifunctionality in vanadium dioxide-integrated metamaterials for switching between dual-band perfect absorption and asymmetric transmission

In this work, we present a theoretical proposal for an actively tunable metamaterial design that integrates vanadium dioxide (VO2). This VO2-integrated design demonstrates the ability to switch between dual-band perfect absorption and asymmetric transmission (AT) functionalities in the near-infrared and mid-infrared spectral ranges. By utilizing the unique properties of VO2, our proposed device achieves broadband absorption across approximately 2.47 μm with polarization independence when VO2 is in its metallic state. Furthermore, it exhibits narrowband absorption with polarization correlation, reaching a linear dichroism value of approximately 0.704. On the other hand, when VO2 is in its insulating state, the metamaterial structure realizes AT of 0.418 for circularly polarized light. We provide physical insight into the operating mechanisms through impedance matching analysis and electric field distributions. The integration of VO2 in this dynamically tunable, multifunctional metamaterial design offers a novel approach to developing reconfigurable nanophotonic and nanosystem technologies.

Multimodal integrated and broadband light-driven antibacterial cellulose fabric based on π-π coupling enhanced intermolecular FRET

Fabrication of antimicrobial photodynamic therapy (aPDT) materials based on organic photosensitizers has garnered considerable attention within functional textiles. However, the UV- or narrow-band absorption range of the photosensitizers results in poor photon utilization of the fabrics, limiting the photodynamic efficiency and wasting solar energy. In this study, a broadband light-driven antibacterial cellulose fabric (CF-ZnPc/NAD) was developed by loading carboxyl-modified zinc(II) phthalocyanine photosensitizer (CAZnPc) and cationic 1,8-naphthalimide fluorescent molecule (NAD) on the fabric via covalent binding and electrostatic adsorption assembly, facilitating the intermolecular π-π coupling and fluorescence resonance energy transfer (FRET) process. There is a 2.54-fold increase in photo-induced ROS generation capacity of CF-ZnPc/NAD via the FRET process compared to that of CF-ZnPc, and it also exhibited a strong photothermal effect (PTT), wherein the temperature of the fabric increased from 24.5 to 53.5 °C within 80 s of illumination (λ > 400 nm, 75 mW/cm2). CF-ZnPc/NAD exhibited strong light-harvesting capacity and a combination of aPDT and PTT, achieving excellent antibacterial performance against Staphylococcus aureus (Gram-positive, S. aureus) and Escherichia coli (Gram-negative, E.coli) with 99.99 % bacterial reduction under 90 min of illumination (λ > 400 nm, 10 ± 1 mW/cm2). This study demonstrates a novel and facile strategy for successfully fabricating high-performance antibacterial cellulose fabrics with potential biomedical prospects.

A terahertz broadband and narrowband switchable absorber based on joint modulation of vanadium dioxide and graphene surfaces

Abstract In this paper, a terahertz broadband and narrowband switchable absorber is proposed. The absorption performance tuning for both broadband and narrowband functions is realized based on the joint modulation of vanadium dioxide (VO2) and graphene surfaces. Concretely, while VO2 is in the metallic state, the absorber achieves broadband absorption function. The overall bandwidth of over 90% absorption is 4.04 THz corresponding to a relative bandwidth of 84%. Through regulating the conductivity of VO2, dynamic tuning of the absorption amplitude is obtained and the modulation depth is 96%. By manipulating the graphene Femi energy and VO2 conductivity simultaneously, dynamic tuning of the absorption bandwidth is realized. In particular, the spectral center frequency of broadband absorption remains stable without drifting during the tuning process. While VO2 is in the insulating state, the absorber achieves narrowband absorption function. Calculated results show that two separate perfect absorption peaks are formed, and the absorption amplitudes are 99.6% and 99.2% respectively. Through regulating the Fermi energy of graphene surface, the dynamic tuning of narrowband absorption frequency is realized. Compared with the ones reported in recent years, our absorber has the advantage on function realization, absorption characteristics and performance tuning.

Narrowband absorption far-red organic photodetector for photoplethysmography.

Narrowband absorption organic semiconductors are highly attractive for spectrally selective photodetection applications requiring lightweight and customizable devices. Although narrowband absorption photodetectors have achieved success in the visible range, far-red (650-750 nm) devices are scarce. The far-red wavelength range is relevant for applications in medical diagnostics, such as photoplethysmography for blood oxygen saturation detection. In this study, a non-fullerene bulk heterojunction organic photodetector with a narrowband response in the far-red spectrum is fabricated. The photodetector exhibits a high detectivity of 5.06 × 1012 Jones at a bias of -2 V. The full-width at half-maximum of the responsivity peak of the photodetector is 85 nm, which is the smallest spectral width among solution-processed devices. The response speed is 11.56 kHz. The photodetector responds within the microsecond range. The potential of the photodetector for blood oxygen saturation measurement is demonstrated.

A DFT study to explore structural, electronic, optical and mechanical properties of lead-free Na2MoXO6 (X = Si, Ge, Sn) double perovskites for photovoltaic and optoelectronic applications

In this study we have performed DFT based calculations on lead-free Na2MoXO6 (X = Si, Ge, and Sn) double perovskites (DPs) for photovoltaic and optoelectronic applications. Trans-Blaha modified Becke-Johnson potential (TB-mBJ) approximation is used to calculate electronic properties of the given materials. All the given perovskites are found in cubic symmetry exhibiting semiconducting nature with energy band gap ∼1.77 eV, 1.65 eV and 1.33 eV, respectively. The calculated values of tolerance factor τ and negative formation energy demonstrate the structural and thermodynamic stabilities of all the investigated compounds. The elastic study demonstrates the ductile and anisotropic nature of Na2MoXO6 (X = Si, Ge, and Sn) compounds. In addition Na2MoXO6 (X = Ge, and Sn) compounds exhibit large absorption coefficient in visible light among the investigated perovskites. Overall the study demonstrates the suitability of investigated compounds for solar cell and other optoelectronic devices because of their narrow band gap and absorption performance.