Numerical studies on a ternary AgInTe2 chalcopyrite thin film solar cell.

This paper theoretically outlines a new n-AlSb/p-AgInTe2/p+-BaSi2 solar cell. The dominance of several factors such as depth, carrier density and defects of every layer on the photovoltaic (PV) outcome has been ascertained applying Solar Cell Capacitance Simulator (SCAPS)-1D computer-based simulator. The AgInTe2 (AIT) solar cell has been probed for finding the role of BaSi2 as a back surface field (BSF) layer. It is revealed that the device power conversion efficiency (PCE) increments from 30% to 34% owing to the use of BaSi2 semiconducting BSF with VOC = 0.90 V, JSC = 43.75 mA/cm2, FF = 86.42%, respectively. The rippling of the output parameters with respect to the change in series and shunt resistances has also been probed and demonstrated. All the findings reveal the prospect of n-AlSb/p-AIT/p+-BaSi2 dual-heterojunction thin film photovoltaic cell.

Theoretical insights into a high-efficiency Sb2Se3-based dual-heterojunction solar cell.

Here, we manifest the design and simulation of an n-ZnSe/p-Sb2Se3/p + -AgInTe2 dual-heterojunction (DH) solar cell which exhibits a prominent efficiency. The performance of the solar cell has been assessed with reported experimental parameters using SCAPS-1D simulator by varying thickness, doping concentration and defect density in each layer. The proposed structure shows an efficiency of 38.6% with V OC = 0.860 V, J SC = 54.3 mA/cm2 and FF = 82.77%, respectively. Such a high efficiency close to Shockley-Queisser (SQ) limit of DH solar cell has been achieved as a result of the longer wavelength photon absorption in the p + -AgInTe2 back surface field (BSF) layer through a tail-states assisted (TSA) two-step photon upconversion phenomenon. These results indicate hopeful application of AgInTe2 as a bottom layer in Sb2Se3-based solar cell to enhance the cell performance in future.

Stress-induced phase-alteration in solution processed indium selenide thin films during annealing.

This article demonstrates the successful synthesis of indium selenide thin films by a spin coating method in air using thiol-amine cosolvents. The synthesized films encountered a transformation from ß-In3Se2 to γ-In2Se3 phase due to mechanical stress during annealing as confirmed from XRD and EDS analysis. The SEM study ensured the homogeneity and uniformity of surface morphology of both phases. The FTIR analysis also confirmed the In-Se stretching vibration bond for both ß-In3Se2 and γ-In2Se3 thin films. The temperature dependent electrical conductivity indicated the semiconducting nature of both phases. The optical transmittance was found to increase with annealing temperatures for both phases. The optical band gaps were estimated to be in the range of 2.60-2.75 and 2.12-2.28 eV for ß-In3Se2 and γ-In2Se3 phases, respectively consistent with the reported values. These results indicate that stress-induced phase transformation in solution-processed indium selenide could be useful in 2D optoelectronic devices in future.

Synthesis of Self-Assembled Randomly Oriented VO2 Nanowires on a Glass Substrate by a Spin Coating Method.

Randomly oriented vanadium dioxide (VO2) nanowires were produced on a glass substrate by spin coating from a cosolvent. SEM studies reveal that highly dense VO2 nanowires were grown at an annealing temperature of 400 °C. X-ray diffraction (XRD) provides evidence of the high crystallinity of the VO2 nanowires-embedded VO2 thin films on the glass substrate at 400 °C. Characterization by high-resolution transmission electron microscopy (HR-TEM) confirmed the formation of VO2 nanowires. The optical band gap of the nanowires-embedded VO2 thin films was also calculated from the transmittance data to be 2.65-2.70 eV. The growth mechanism of the solution-processed semiconducting VO2 nanowires was proposed based on both solvent selection and annealing temperature. Finally, the solar water splitting ability of the VO2 nanowires-embedded VO2 thin films was demonstrated in a photoelectrochemical cell (PEC).

Electronic Structure of In3-x Se4 Electron Transport Layer for Chalcogenide/p-Si Heterojunction Solar Cells.

In this article, we perform density functional theory calculation to investigate the electronic and optical properties of newly reported In3-x Se4 compound using CAmbridge Serial Total Energy Package (CASTEP). Structural parameters obtained from the calculations agree well with the available experimental data, indicating their stability. In the band structure of In3-x Se4 (x = 0, 0.11, and, 0.22), the Fermi level (E F) crossed over several bands in the conduction bands, which is an indication of the n-type metal-like behavior of In3-x Se4 compounds. On the other hand, the band structure of In3-x Se4 (x = 1/3) exhibits semiconducting nature with a band gap of ∼0.2 eV. A strong hybridization among Se 4s, Se 4p and In 5s, In 5p orbitals for In3Se4 and that between Se 4p and In 5p orbitals were seen for ß-In2Se3 compound. The dispersion of In 5s, In 5p and Se 4s, Se 4p orbitals is responsible for the electrical conductivity of In3Se4 that is confirmed from DOS calculations as well. Moreover, the bonding natures of In3-x Se4 materials have been discussed based on the electronic charge density map. Electron-like Fermi surface in In3Se4 ensures the single-band nature of the compound. The efficiency of the In3-x Se4/p-Si heterojunction solar cells has been calculated by Solar Cell Capacitance Simulator (SCAPS)-1D software using experimental data of In3-x Se4 thin films. The effect of various physical parameters on the photovoltaic performance of In3-x Se4/p-Si solar cells has been investigated to obtain the highest efficiency of the solar cells. The optimized power conversion efficiency of the solar cell is found to be 22.63% with V OC = 0.703 V, J SC = 38.53 mA/cm2, and FF = 83.48%. These entire theoretical predictions indicate the promising applications of In3-x Se4 two-dimensional compound to harness solar energy in near future.