Design and analysis of titanium nitride plasmonic nanoparticle embedded and upconverter incorporated kesterite tandem solar cell

Abstract

This thesis presents the design, optimization, and performance analysis of titanium nitridenanoparticle embedded and upconverter incorporated kesterite solar cells.We systematicallystudiedscatteringcross-sectionandabsorptionenhancementbynanoparticles(NPs)ofalter-nativematerial,TiN.Atfirst,weperformedacomparativeperformanceanalysisofTiNwithnoble metals, Au and Ag to establish its functionality as a plasmonic material. Afterward,weexploreddifferent-shapedplasmonicnanosystems,whichconsistedofdimer,monomer,and bowtie-shaped NPs.Moreover, we determined the total scattering cross-section, thefraction of light scattered into the substrate, light scatter into the substrate, the absorptioncross-section, and spatial mapping of the electric field in the plasmonicnanosystems. Ad-ditionally, we studied the polarization-sensitive performance varying the light polarizationangle. We conducted a shape-dependent comparative analysis of the nanoparticles. We ex-amined the impact of the dielectric coating of the nanoparticles. We considered monomerspherical,dimerspherical,andbowtie-shapedTiNNPsonCZTSthinfilm-basedsolarcellsand found that bowtie-shaped had the best electrical and optical performance. In the solarcell, the nanoparticle with the best performance was utilized. Instead of using silicon cells,kesterite solar cells are utilized to increase solar cell efficiency.Our suggested solar cellconceptfeaturestandemsolar,andanupconverterlayerisinsertedtoincreaselighttrappingefficiency. We conducted comparison analyses with the metals Ag, Au, and Al to ascertainthe performance of TiN as a plasmonic material. TiN NP had the higher absorption cross-section, Qaband fraction of light scattered into the substrate, fsubvalues greater than thoseof Ag, Au, and Al.TiN dimer exhibited better absorption enhancement, g for the wholespectral range than Ag, Au, and Al dimers. Utilizing TiN-based plasmonic nanostructures,we demonstrated that the fsubcan be tuned by varying the shape, size, thickness, dielectricthickness, and source angle. Moreover, total scattering in the wavelength range of the solarspectrum was modulated.The scattering performance improved for the thicker dielectriclayer. Among the nanostructures, the bowtie shape showed a better light absorption cross-section.Solar cells based on the kesterite mineral structure and its alloys stand out fromotherthin-filmsolarcellsduetotheirearth-abundanceandnon-toxicity.Incorporatingplas-monic nanoparticles with kesterite opens a promising path of light trapping efficiency. Themain losses in solar cells result from the incomplete utilization of the solar spectrum. Theotherwise-unused sub-bandgap photons can be utilized by adding an upconverting layer onasolarcell.For100nmthickness,gwasgreaterthan1forthewholespectralrange,andthemaximum value was ∼1.2.The optimal thick bowtie-shaped NP had the highest efficiency, ηat26.27%andhadtheopencircuitvoltageVoc=0.58V,andshortcircuitcurrentdensity,Jsc =54.01 mA/cm2.The absorbed power for bowtie-shaped TiN NP incorporation enhancedthe average absorption from ∼61% to ∼88% for the kesterite cell.The incorporation ofupconverterlayerYAGincreasedthesolarcellefficiencyupto∼28.90%