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Synthesizing and characterizing novel flexible polymeric bio-nanocomposites for advanced applications in the medical, optoelectronic, and energy sectors has become an interesting topic of research worldwide. This work reports the influence of nickel molybdenum oxide nanocrystals (NiMoO4 NC) on the structure, electrical features, and optical factors of a starch/polyethylene oxide (St/PEO) blend. The analyses carried out by the transmission electron microscope X-ray diffraction (XRD), energy-dispersive spectroscopy (EDS), and FTIR techniques displayed that the sol–gel prepared NiMoO4 composed of nanoparticles/nanorods, crystallized in a monoclinic structure with high purity. XRD, FTIR, and scanning electron microscopy, field-emission mode, (FE-SEM) showed that the semi-crystalline and porous structure of the nanocomposites was influenced by the uniform filler distribution. The effect of NiMoO4 NC level on the dielectric permittivity, loss factor, and ac conductivity of St/PEO was studied under heating, and at frequencies up to 7 MHz. Moreover, various optical factors (transmittance in the UV–vis-NIR wavelengths, extinction coefficient, band gap, optical-dielectric loss, and index of refraction (n)) were also evaluated and discussed. The films displayed dual direct/indirect band gaps E g op . The direct (indirect) E g op narrowed from 4.8 to 4.3 eV (3.9 to 3.0 eV) for the high-energy region. NiMoO4 NC changed the n behavior to a wave-like pattern with a significant increase to 3.5˗5.0. The structural changes, as well as the related dielectric and optical enhancements, make NiMoO4/St/PEO materials ideal candidate semiconductors for high refractive index and energy-storing applications. [ABSTRACT FROM AUTHOR]

Recently, ternary Al2CdX4 (X = S, Se, Te) chalcogenides have emerged as excellent active layers in thin film photovoltaic cells due to their excellent light harvesting properties. These materials have high conductivity and are p-type doped making them a viable option to be used as hole transport layers (HTLs) in perovskite solar cells (PSCs). In this study the hetero-junction compatibility of chalcogenides with the lead-free MAGeI3 perovskite were investigated in detail. Three different PSC cells were modelled in SCAPS-1D. Analysis of energy band alignment, band offsets, electric potential, JV, current profile, recombination, absorption and quantum efficiency were carried out to find their suitability. After that the optimization of perovskite thickness, HTL doping, reflection layer concentration and anode work function were carried out to unlock the full potential of the PSCs, which improved the PCE by more than 6%. Finally, the stability analysis of the PSCs for interface defects and temperature was done. The study found that the least compatible material was Al2CdS4 due to its large valance band offset of 0.89 eV, producing a PCE of 0.05%. While the most compatible was Al2CdSe4, which produced the highest performance with PCE of 25.93%, Jsc of 17.02 mA/cm2, Voc of 1.75 V and FF of 87.25%. [ABSTRACT FROM AUTHOR]

This work presents a facile approach for controlling the optical and electrical parameters of a biopolymeric matrix for optoelectronics. Vanadium oxide (V2O5) and chromium oxide (Cr2O3) nanoparticles (NPs) were prepared and incorporated into the carboxymethylcellulose/polyethylene glycol (CMC/PEG) blend by simple chemical techniques. Transmission electron microscopy (HR-TEM), and X-ray diffraction (XRD) data showed that V2O5 and Cr2O3 exhibited spherical shapes with sizes in the range of 40–50 nm and 10–20 nm, respectively. In addition, the blend's degree of crystallinity was sensitive to the V2O5 and Cr2O3 doping ratios. The scanning electron microscopy (FE-SEM) and the elemental chemical analysis (EDAX) used to study the filler distribution inside the blend, and confirmed the existence of both V and Cr in the matrix. Fourier transform infrared (FTIR) spectroscopy showed that the dopants significantly affected the blend reactive (C–O–C, OH, and C=O) groups. The stress–strain curves illustrated the reinforcing effect of the dopants up to 1.0 wt\% Cr2O3/V. The transmittance and absorption index spectra in the visible-IR wavelengths decreased with increasing filler content. Utilizing Tauc's relation and (optical) dielectric loss, the direct (indirect) band gap narrowed from 5.6 (4.5) eV to 4.7 (3.05) eV at 1.0 wt\% Cr2O3/V. All films have an index of refraction in the range of 1.93–2.17. AC conductivity was improved with increasing filler content and temperature. The energy density at 50 °C is in the range of 1–3 J/m3. The influence of V2O5 and Cr2O3 content on the optical conductivity, dielectric constant, loss, and dielectric modulus of CMC/PEG was reported. These enhancements in electrical and optical properties, along with the potential for band gap engineering, offer promising prospects for advanced applications in optoelectronics and energy-related fields. [ABSTRACT FROM AUTHOR]

Solar energy is the most used renewable energy source. CZTSSe uses earth-abundant elements and has promising optoelectronic properties, resulting in becoming a viable alternative to thin film PV. This work provides design guidelines for CZTSSe-based solar cells, where CZTSSe has a tunable affinity and energy gap. The analysis is based on incorporating a ternary compound material to serve as an electron transport material (ETM). In this regard, CdZnS is a potential candidate that can be utilized as an electron transport layer whose affinity and energy gap can be tuned to adjust the band alignment at the ETL/CZTSSe interface. In order to design a high-efficiency solar cell, one has to tune both the ETL and absorber layers to have a suitable conduction band offset (CBO), thereby minimizing the non-radiative recombination which, in turn, boosts the power conversion efficiency (PCE). Thus, in our presented simulation study, we provide a codesign of alloy compositions of both the CZTSSe photoactive layer and the CdZnS ETL using SCAPS-1D simulation. It is found that using the codesign of alloy compositions of the ternary compound ETL and the absorber enhances the PCE by about 2% and, more importantly, overcomes the main issue in CZTSSe which is its open-circuit voltage (VOC) deficit. Furthermore, upon optimizing the thickness and doping of both the ETL and absorber layer, as well as the bulk defect of the absorber layer, a PCE of 17.16% is attained in this study, while the calibrated PCE based on a previously published experimental work was 12.30%. [ABSTRACT FROM AUTHOR]

The low bandgap antimony selenide (Sb2Se3) and wide bandgap organic solar cell (OSC) can be considered suitable bottom and top subcells for use in tandem solar cells. Some properties of these complementary candidates are their non-toxicity and cost-affordability. In this current simulation study, a two-terminal organic/Sb2Se3 thin-film tandem is proposed and designed through TCAD device simulations. To validate the device simulator platform, two solar cells were selected for tandem design, and their experimental data were chosen for calibrating the models and parameters utilized in the simulations. The initial OSC has an active blend layer, whose optical bandgap is 1.72 eV, while the initial Sb2Se3 cell has a bandgap energy of 1.23 eV. The structures of the initial standalone top and bottom cells are ITO/PEDOT:PSS/DR3TSBDT:PC71BM/PFN/Al, and FTO/CdS/Sb2Se3/Spiro-OMeTAD/Au, while the recorded efficiencies of these individual cells are about 9.45% and 7.89%, respectively. The selected OSC employs polymer-based carrier transport layers, specifically PEDOT:PSS, an inherently conductive polymer, as an HTL, and PFN, a semiconducting polymer, as an ETL. The simulation is performed on the connected initial cells for two cases. The first case is for inverted (p-i-n)/(p-i-n) cells and the second is for the conventional (n-i-p)/(n-i-p) configuration. Both tandems are investigated in terms of the most important layer materials and parameters. After designing the current matching condition, the tandem PCEs are boosted to 21.52% and 19.14% for the inverted and conventional tandem cells, respectively. All TCAD device simulations are made by employing the Atlas device simulator given an illumination of AM1.5G (100 mW/cm2). This present study can offer design principles and valuable suggestions for eco-friendly solar cells made entirely of thin films, which can achieve flexibility for prospective use in wearable electronics. [ABSTRACT FROM AUTHOR]

The advancement of lead-free double perovskite materials has drawn great interest thanks to their reduced toxicity, and superior stability. In this regard, Cs2AgBiBr6 perovskites have appeared as prospective materials for photovoltaic (PV) applications. In this work, we present design and numerical simulations, using SCAPS-1D device simulator, of Cs2AgBiBr6-based double perovskite solar cell (PSC). The initial calibrated cell is based on an experimental study in which the Cs2AgBiBr6 layer has the lowest bandgap (Eg = 1.64 eV) using hydrogenation treatment reported to date. The initial cell (whose structure is ITO/SnO2/Cs2AgBiBr6/Spiro-OMeTAD/Au) achieved a record efficiency of 6.58%. The various parameters that significantly affect cell performance are determined and thoroughly analyzed. It was found that the conduction band offset between the electron transport layer (ETL) and the Cs2AgBiBr6 layer is the most critical factor that affects the power conversion efficiency (PCE), in addition to the thickness of the absorber film. Upon engineering these important technological parameters, by proposing a double ETL SnO2/ZnO1-xSx structure with tuned absorber thickness, the PCE can be boosted to 14.23%. [ABSTRACT FROM AUTHOR]

We study the spectral response of a one-dimensional dielectric–metal photonic-crystal absorber. The reflection and absorption spectra in the frequency range 0.1–10 THz are obtained by applying a transfer-matrix method. The influence of different factors such as the incidence angle, the thickness and the materials of metallic and dielectric layers on the absorption spectrum of our absorber is explored. Finally, we offer a high-efficient photonic-crystal absorber based on Si–Ni with the free spectral range 1.46 THz and the finesse 2.496. The calculations reveal that high enough absorption (99.37%) and reflection (96.77%) can be achieved for our absorber. Therefore, it can be used as both a perfect absorber and a perfect reflector over a wide range of THz frequencies. [ABSTRACT FROM AUTHOR]