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Recent trends of photovoltaics account for the conversion efficiency limit making them more cost effective. To achieve this we have to leave the golden era of silicon cell and make a path towards III–V compound semiconductor groups to take advantages like bandgap engineering by alloying these compounds. In this work we have used a low bandgap GaSb material and designed a single junction (SJ) cell with a conversion efficiency of 32.98%. SILVACO ATLAS TCAD simulator has been used to simulate the proposed model using both Ray Tracing and Transfer Matrix Method (under 1 sun and 1000 sun of AM1.5G spectrum). A detailed analyses of photogeneration rate, spectral response, potential developed, external quantum efficiency (EQE), internal quantum efficiency (IQE), short-circuit current density (J${}_{\mathrm{\text{SC}}}$), open-circuit voltage (V${}_{\mathrm{\text{OC}}}$), fill factor (FF) and conversion efficiency ($\eta$) are discussed. The obtained results are compared with previously reported SJ solar cell reports.

In this paper, a novel approach is presented for the first time to increase the energy gap of Si-based material by doping carbon atoms into Si-based material structures. The structural electronic properties and mechanical properties of ${\mathrm{\text{Si}}}_{1-x}{\mathrm{\text{C}}}_x$ ($x=0.05$, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4) are investigated using a first-principles calculation method. Bandgaps of the ${\mathrm{\text{Si}}}_{1-x}{\mathrm{\text{C}}}_x$ shells were found to have, respectively, quadratic relationships with the Carbon content $(x)$. Meanwhile, the electronic bandgap of Si-based material can be increased by 0.334 eV due to the carbon substitutions. The optimal structure is ${\mathrm{\text{Si}}}_{0.7}{\mathrm{\text{C}}}_{0.3}$ and the elastic constants and phono calculations reveal that ${\mathrm{\text{Si}}}_{0.7}{\mathrm{\text{C}}}_{0.3}$ is mechanically and dynamically stable. Finally, two different heavy doped ${\mathrm{\text{Si}}}_{0.7}{\mathrm{\text{C}}}_{0.3}$ have been investigated and the results indicate that the $p$-type and $n$-type doped ${\mathrm{\text{Si}}}_{0.7}{\mathrm{\text{C}}}_{0.3}$ do produce shallow levels. This study can be a theoretical guidance to improve the bandgap of Si-based semiconductors. In addition, ${\mathrm{\text{Si}}}_{0.7}{\mathrm{\text{C}}}_{0.3}$ show superior bandgap and material properties enabling ${\mathrm{\text{Si}}}_{0.7}{\mathrm{\text{C}}}_{0.3}$ power device operation at higher temperatures, voltages than current Si-based power semiconductor device.

Gamma irradiation-induced chemical decomposition and related phase transformation from SnO₂ nanoparticles (NPs) to SnO have been studied using X-ray diffraction (XRD), Raman spectroscopy, transmission electron microscopy (TEM) and UV–Vis spectroscopy. XRD studies show that the SnO₂NP_S are crystalline in nature with rutile structure. Crystallinity of the NPs increases with the increase of gamma irradiation doses, which is consistent with the results of TEM. At high gamma irradiation doses, SnO phase appears from SnO₂ matrix, which pushes the SnO₂ phase toward stoichiometry. The band gap energy has been found in the range of 3.84–3.76eV, larger than the band gap of bulk SnO₂. The larger band gap is attributed due to small particle size, which is confirmed by TEM studies. Optical reflectance and band gap decrease with the increase of gamma irradiation doses due to creation of defects. This property of SnO₂ NPs makes it suitable for use in optical devices.

This paper describes some of our efforts in the area of nanostructured thin film architectures. The resulting interfacial hybrid assemblies are built from (1) organic/polymeric objects based on dendrimer systems, from (2) surface-functionalized Au nanoparticles, and (3) from a variety of semiconducting quantum dots. Dendrimers as polymeric building blocks with a strictly monodisperse particle size distribution in the nanometer range can be functionalized in the core, the scaffold, or at the periphery, thus offering interesting hybrid materials for a wide range of applications. The combination with Au clusters and their local surface plasmon resonances suggests new strategies for optoelectronic devices or unconventional bio-sensor platforms. The possibility of tuning the luminescent properties of semiconducting nanoparticles by size or compositional bandgap engineering complements the assembly kit with building blocks for supramolecular thin film nanocomposite materials.

By acoustically irradiating pristine, white, electrically insulating h-BN in aqueous environment we were able to invert its material properties. The resulting dark, electrically conductive h-BN (referred to as partially oxidized h-BN or PO-hBN) shows a significant decrease in optical transmission (>60%) and bandgap (from 5.46 eV to 3.97 eV). Besides employing a wide variety of analytical techniques (optical and electrical measurements, Raman spectroscopy, SEM imaging, EDS, X-Ray diffraction, XPS and TOF-SIMS) to study the material properties of pristine and irradiated h-BN, our investigation suggests the basic mechanism leading to the dramatic changes following the acoustic treatment. We find that the degree of inversion arises from the degree of h-BN surface or edge oxidation which heavily depends on the acoustic energy density provided to the pristine h-BN platelets during the solution-based process. This provides a facile avenue for the realization of materials with tuned physical and chemical properties that depart from the intrinsic behavior of pristine h-BN.