A Review: Application of Doped Hydrogenated Nanocrystalline Silicon Oxide in High Efficiency Solar Cell Devices.

Due to the unique microstructure of hydrogenated nanocrystalline silicon oxide (nc-SiO:H), the optoelectronic properties of this material can be tuned over a wide range, which makes it adaptable to different solar cell applications. In this work, the authors review the material properties of nc-SiO:H and the versatility of its applications in different types of solar cells. The review starts by introducing the growth principle of doped nc-SiO:H layers, the effect of oxygen content on the material properties, and the relationship between optoelectronic properties and its microstructure.

Method for bandgap interpolation of perovskite's spectral complex refractive index.

Lead halide perovskites are a promising class of materials for solar cell applications. The perovskite bandgap depends on the material composition and is highly tunable. Opto-electrical device modelling is commonly used to find the optimum perovskite bandgap that maximizes device efficiency or energy yield, either in single junction or multi-junction configuration.

Electrical performance of a fully reconfigurable series-parallel photovoltaic module.

Reconfigurable photovoltaic modules are a promising approach to improve the energy yield of partially shaded systems. So far, the feasibility of this concept has been evaluated through simulations or simplified experiments. In this work, we analyse the outdoor performance of a full-scale prototype of a series-parallel photovoltaic module with six reconfigurable blocks.

Vacuum Deposited Perovskites with a Controllable Crystal Orientation.

The preferential orientation of the perovskite (PVK) is typically accomplished by manipulation of the mixed cation/halide composition of the solution used for wet processing. However, for PVKs grown by thermal evaporation, this has been rarely addressed. It is unclear how variation in crystal orientation affects the optoelectronic properties of thermally evaporated films, including the charge carrier mobility, lifetime, and trap densities.

Ray-optics study of gentle non-conformal texture morphologies for perovskite/silicon tandems.

We investigate gentle front side textures for perovskite/silicon tandem solar cells. These textures enhance the absorption of sunlight, yet are sufficiently gentle to allow deposition of an efficient perovskite top cell. We present a tandem solar cell with such gentle texture, fabricated by Kaneka corporation, with an efficiency as high as 28.

Comparing optical performance of a wide range of perovskite/silicon tandem architectures under real-world conditions.

Since single junction c-Si solar cells are reaching their practical efficiency limit. Perovskite/c-Si tandem solar cells hold the promise of achieving greater than 30% efficiencies. In this regard, optical simulations can deliver guidelines for reducing the parasitic absorption losses and increasing the photocurrent density of the tandem solar cells.

High-Mobility Hydrogenated Fluorine-Doped Indium Oxide Film for Passivating Contacts c-Si Solar Cells.

Broadband transparent conductive oxide layers with high electron mobility () are essential to further enhance crystalline silicon (c-Si) solar cell performances. Although metallic cation-doped InO thin films with high (>60 cm V s) have been extensively investigated, the research regarding anion doping is still under development. In particular, fluorine-doped indium oxide (IFO) shows promising optoelectrical properties; however, they have not been tested on c-Si solar cells with passivating contacts.

Understanding the nano-photonics absorption limit in both front-side and front/rear-side textured slabs.

Surface texturing is one of the main techniques to enhance light absorption in solar cells. In thin film devices, periodic texturing can be used to excite the guided resonances supported by the structure. Therefore, total absorption is enhanced largely due to the excitation of these resonances.

Solar harvesting based on perfect absorbing all-dielectric nanoresonators on a mirror.

The high-index all-dielectric nanoantenna system is a platform recently used for multiple applications, from metalenses to light management. These systems usually exhibit low absorption/scattering ratios and are not efficient photon harvesters. Nevertheless, by exploiting far-field interference, all-dielectric nanostructures can be engineered to achieve near-perfect absorption in specific wavelength ranges.

Optical study of back-contacted CIGS solar cells.

A novel back-contacted solar cell based on a submicron copper indium gallium (di)selenide (CIGS) absorber is proposed and optically investigated. First, charge carrier collection feasibility is studied by band diagram analysis. Then, two back-contacted configurations are suggested and optimized for maximum current production.

Geometrical optimisation of core-shell nanowire arrays for enhanced absorption in thin crystalline silicon heterojunction solar cells.

Elongated nanostructures, such as nanowires, have attracted significant attention for application in silicon-based solar cells. The high aspect ratio and characteristic radial junction configuration can lead to higher device performance, by increasing light absorption and, at the same time, improving the collection efficiency of photo-generated charge carriers. This work investigates the performance of ultra-thin solar cells characterised by nanowire arrays on a crystalline silicon bulk.

Oxidation-Induced Structure Transformation: Thin-Film Synthesis and Interface Investigations of Barium Disilicide toward Potential Photovoltaic Applications.

Barium disilicide (BaSi) has been regarded as a promising absorber material for high-efficiency thin-film solar cells. However, it has confronted issues related to material synthesis and quality control. Here, we fabricate BaSi thin films via an industrially applicable sputtering process and uncovered the mechanism of structure transformation.

Feature issue introduction: light, energy and the environment, 2017.

The editors introduce the feature issue on "Energy, Light and the Environment (LEE) 2017", which is based on the topics presented at a congress of the same name held in Boulder, CO, US, from November 6 to November 9. This feature issue presents 13 papers selected from the voluntary submissions by attendees who presented at the progress and have extended their work into complete research articles. The feature issue highlights contributions from authors who presented their research at this congress.

Quenching Mo optical losses in CIGS solar cells by a point contacted dual-layer dielectric spacer: a 3-D optical study.

A 3-D optical modelling was calibrated to calculate the light absorption and the total reflection of fabricated CIGS solar cells. Absorption losses at molybdenum (Mo) / CIGS interface were explained in terms of plasmonic waves. To quench these losses, we assumed the insertion of a lossless dielectric spacer between Mo and CIGS, whose optical properties were varied.

Back-contacted BaSi solar cells: an optical study.

We present the optical investigation of a novel back-contacted architecture for solar cells based on a thin barium (di)silicide (BaSi) absorber. First, through the analysis of absorption limits of different semiconducting materials, we show the potential of BaSi for photovoltaic applications. Then, the proposed back contacted BaSi solar cell design is investigated and optimized.

Decoupled front/back dielectric textures for flat ultra-thin c-Si solar cells.

The optical analysis of optically-textured and electrically-flat ultra-thin crystalline silicon (c-Si) slabs is presented. These slabs were endowed with decoupled front titanium-dioxide (TiO) / back silicon-dioxide (SiO) dielectric textures and were studied as function of two types of back reflectors: standard silver (Ag) and dielectric modulated distributed Bragg reflector (MDBR). The optical performance of such systems was compared to that of state-of-the-art flat c-Si slabs endowed with so-called front Mie resonators and to those of similar optical systems still endowed with the same back reflectors and decoupled front/back texturing but based on textured c-Si and dielectric coatings (front TiO and back SiO).

Ambiguities in optical simulations of nanotextured thin-film solar cells using the finite-element method.

The optimal morphology of nanotextured interfaces, which increase the photocurrent density of thin-film solar cells, is still an open question. While random morphologies have the advantage to scatter light into a broad angular range, they are more difficult to assess with Maxwell solvers, such as the finite-element method (FEM). With this study we aim to identify necessary requirements on the unit cell design for the accurate simulation of nanotextured thin-film solar cells with FEM.

Plasmonic silicon solar cells: impact of material quality and geometry.

We study n-i-p amorphous silicon solar cells with light-scattering nanoparticles in the back reflector. In one configuration, the particles are fully embedded in the zinc oxide buffer layer; In a second configuration, the particles are placed between the buffer layer and the flat back electrode. We use stencil lithography to produce the same periodic arrangement of the particles and we use the same solar cell structure on top, thus establishing a fair comparison between a novel plasmonic concept and its more traditional counterpart.