We explore the ability of hyperuniform disordered structures to enhance light absorption in thin-film solar cells architectures and perform full electromagnetic wave simulations that unveil light trapping techniques capable to attain large absorption enhancements up 85% over the visible spectrum. We predicate this enhancement to the interplay between two key physical phenomena: ultimate control over the light diffraction via a hyperuniformly-patterned surface layer which results in a highly efficient coupling of light to the quasi-guided modes of the absorbing silicon film and a concomitant minimisation of the reflection losses atop of the solar absorber. Our experimental results further validate this approach, showcasing an impressive 65% enhancement in solar light absorption in a freely suspended 1-μm c-Si membrane across the spectral range from 400 to 1050nm. We also explore applications of hyperuniform disordered architectures to high-efficiency solar-thermal absorbers.

Optimizing the bandgap energy for a perovskite cell typically requires the complex refractive index, which are obtained from spectroscopic ellipsometry measurements. While these measurements are usually available for a few discrete bandgap energies, it is desired to have them in continuous range to find the optimal bandgap energy. We propose a new method for generating the complex refractive index, based on the interpolation of a few measured data sets. The Forouhi-Bloomer model is used to fit the measured data. Then a linear regression is applied to the fit parameters with respect to the bandgap energy. From the interpolated parameters, the refractive index curve of perovskite with any desired bandgap energy is finally reconstructed. We validated our method by simulating the absorptance of a single junction perovskite cell and a perovskite/silicon tandem cell, showing that our method can accurately model the refractive index.

Luminescent coupling is a characteristic of multi-junction solar cells which has often been neglected in models of their performance. The effect describes the absorption of light emitted from a higher band gap semiconductor by a lower band gap semiconductor. In this way, light which might have been lost can be utilized for current generation. We present a framework for modeling this effect in both planar layer stacks and devices with periodic nanostructuring. As a case study, we evaluate how luminescent coupling is affected by the inclusion of nanostructuring in a perovskite silicon tandem solar cell. We find that nanostructuring, while reducing the reflection loss for tandem solar cells also reduces the luminescent coupling, allowing more light to be emitted to the surroundings, when compared to planar devices. This highlights the need to include modeling of this effect into optimization schemes in order to find the trade-off between these two effects.

In this work, a theoretical study of luminescent solar concentrators (LSCs) based on stacked doped poly(methyl methacrylate) polymer optical fibres (POFs) has been carried out by means of Monte Carlo simulations. Two different dopants, namely the organic dyes lumogen red and lumogen yellow, uniformly distributed in the cross-sections of the fibres, have been employed in all simulations. Several layers of POFs doped with two dyes arranged in different possible orders in the stack of layers have been considered. Through a comparative analysis of the output irradiances from the different set-ups, this work does not only clarify how to improve the concentration factor, but also the underlying physical and geometrical reasons for the variations in the performance achieved from one of the tested arrangements to another.

The selection of polymers for the packaging of emerging PV technologies like organic or perovskite solar cells is a critical aspect of ensuring the long-term reliability and performance of PV modules. Careful consideration should be given to potential degradation products, permeation properties, and possible incompatibilities among different materials within the module. This holistic approach to material selection can contribute to the development of more durable and efficient PV modules, addressing challenges related to degradation and failure modes beyond just the solar cells themselves.

Perovskite materials have drawn significant attention due to their distinct characteristics and increasing optoelectronic applications. The triple cation (Cs/MA/FA) perovskite precursor solution is commonly synthesized using the conventional perovskite stirring method (CSM) regulated within a nitrogen glovebox. However, the process requires a significant amount of time for preparation and limits the fabrication conditions in an ambient environment, hence impeding their potential for large-scale applications and ambient environment stability. Here, a triple cation perovskite (Cs_0.1(MA_0.17FA_0.83)_0.9Pb(Br_0.17I_0.83)₃) precursor solution was prepared using the microwave-assisted synthesis (MAS) method and fabricated as a perovskite transistor in a “fully-ambient air” environment. The stability of perovskite films was evaluated by measuring their optical properties and comparing the characteristics of MAS-perovskite solution to the conventional stirring method (CSM). The perovskite films made via MAS exhibited an anomalous shift towards shorter wavelengths and an increase in linewidth as the temperature increased, highlighting the distinctive characteristics of the triple cation perovskite that was produced. These results were later analyzed and fitted to investigate the induced lattice thermal expansion, structural phase transition, and electron phonon interactions that highlighted the enhanced crystal quality from the MAS-perovskite films. Aside from the seven-fold PL enhancements, the fabrication of MAS-perovskite transistors in a completely ambient environment resulted in a ten-fold increase in electron carrier mobility compared to the CSM-perovskite devices indicating a large improvement in the crystalline formation mechanism of MAS-perovskite materials. The success in preparing the ambient-fabricated is beneficial for pushing the large-scale and efficient optoelectronic devices.

Luminescent solar concentrator (LSC) is an optoelectronic device which converts direct and diffused sunlight into electricity when coupled with photovoltaic (PV) cells around its edge. Large Stokes shift is beneficial to minimize the reabsorption loss and improve the overall efficiency of LSCs. In this study, the fabricated Gold-doped silver nanoclusters embedded in Polyvinylpyrrolidone (Au-AgNCs@PVP) matrix exhibited significantly large Stokes shift of about ~200nm with spectral overlap integral of 0.03 and Urbach tail observed on the absorption spectra along ~480 to 600nm. This is a typical behavior of emissions from self-trapped excitons (STEs) due to the lattice distortion caused by a strong exciton-phonon coupling. The strong coupling is evident by having small steepness constant around ~0.32 extracted from the temperature dependent Urbach energy, thus, proving the photoluminescence originating from STEs.

Despite the great promotion of perovskite solar cells, the presence of defect trap states at the surfaces and grain boundaries has a negative influence on photovoltaic functionality, primarily due to the polycrystalline nature of perovskite film formation. Motivated by porphyrin molecules excellent charge mobility and various optical transitions in the visible region, we introduce a simple zinc (II)β-tetra-bromo-meso-tetra-phenyl-porphyrin as an additive in the perovskite layer to improve the performance and stability of planar perovskite solar cells. The modified electron density distribution of the molecule developed on electronegative Br sites enables the passivation of charged defect states. Its compatible energy levels and high charge mobility lead to better electron-hole transport through the perovskite layer and defect passivation in the grain boundaries. Moreover, it also has a positive effect on the perovskite film formation quality. As a result, the efficiency of the best device is up to 18.5%, a factor of 15% increase to that of the reference cell with a value of 16.1%, which is superior in planar device structure with copper indium disulfide (CIS) as a hole transport material and carbon as back contact. Furthermore, enhanced hydrophobicity and crystalline quality improve the stability of devices, and the modified device maintained 96% of its initial efficiency after 40 days in comparison with the control device with 38% drop in its performance.

Concentrating photovoltaic technology (CPV) offers higher efficiency than flat photovoltaic technology (PV), but one of the obstacles to its commercial diffusion arises from the complexity and bulkiness of the optical systems (with primary and secondary optics), which require precise and expensive alignments. New hybrid CPV/PV modules, that use innovative solar tracking strategies, allow using new optics solutions to overcome the limitations related to the sun incidence angles on the module, thus simplifying the optical design. In this contribution, a new solar concentrator for innovative hybrid CPV/PV modules using aspherical and non-radial symmetric lens is simulated and experimentally tested. These optics exploit the asymmetry in the kinematics of the tracking system along the two orthogonal tracking axes, allowing to get light transmittance higher than 80%, within the 300 to 1800nm spectral range, despite the inevitable infrared absorption bands and the absence of AR coating. The solar concentrator only consists of a single thin primary lens in PMMA, with a geometric concentration factor of 400X. The lens shape was designed and optimized for multiple incidence angles, to maximize performance at various operating conditions with acceptance angle ranges of ±17° and ±5°, in the two orthogonal directions. The optical system, mounted on a test bench, was characterized indoor with a quasi-collimated Xenon lamp, and the results were in good agreement with the simulations. The new optics represents a promising solution for the development of next-generation PV modules, characterized by high energy yields, low costs and reduced environmental impact.

Solar cell technology plays a crucial role in the sustainable energy landscape, offering a promising avenue for renewable energy generation. In this study, we have presented a physical device simulation of a solar cell using Silvaco TCAD. The objective of this research is to investigate the impact of various parameters on the solar cell's efficiency and explore them for enhancing cell’s performance. In general, a solar cell is a composite of several key components, including absorber layer, charge transport layers, contacts, and anti-reflection coating. This study encompasses the physical processes occurring within the solar cell, such as carrier generation, recombination, and transport. In this study, the parameters such as absorber layer thickness, doping concentration, and contact materials are taken as design parameters. The employment of various suitable contact materials resulted in reduced resistive losses and improved the charge extraction mechanism. Through rigorous simulation and analysis, we have identified the optimum parameter combination leading to an enhanced efficiency of the solar cell. After optimizing the absorber with a thickness of 200 microns was subjected to varying doping concentrations in the BSF⁺ layer, ranging from 10¹⁵ to 10²⁰ cm^-3. The photovoltaic characteristics of the proposed design are found to be V_oc of 521.7mV, J_sc of 43.94 mAcm^-2, FF of 77.98%, and an efficiency of 17.88%. Our research will advance solar cell technology, boosting conversion efficiency. Practical implications for designing and optimizing solar cell structures will benefit manufacturers and researchers. This study also lays the groundwork for future innovations in materials and device architectures, leading to more efficient, lightweight, and cost-effective solar cells, promoting sustainable energy solutions.