The efficiency of perovskite/silicon tandem solar cells has exceeded the previous record for III-V-based dual-junction solar cells. This shows the high potential of perovskite solar cells in multi-junction applications. Perovskite/perovskite/silicon triple-junction solar cells are now the next step to achieve efficient and low-cost multi-junction solar cells with an efficiency potential even higher than that for dual-junction solar cells.
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November 2020
Titanium oxide (TiO) has recently emerged as an electron-selective passivating contact for solar cell and semiconductor device applications. The mechanism behind this function has been attributed to the lower energy barrier for electrons than holes at the TiO/semiconductor interface. Here we report an antithetic function of TiO nanolayers (∼5 nm), which were grown by atomic layer deposition (ALD) on either planar or textured crystalline silicon (Si) without a buffer layer, acting as efficient -selective contacts with excellent surface passivation.
View Article and Find Full Text PDFPerovskite silicon tandem solar cells have the potential to overcome the efficiency limit of single-junction solar cells. For both monolithic and mechanically stacked tandem devices, a semi-transparent perovskite top solar cell, including a transparent contact, is required. Usually, this contact consists of a metal oxide buffer layer and a sputtered transparent conductive oxide.
View Article and Find Full Text PDFPerovskite solar cells have become a game changer in the field of photovoltaics by reaching power conversion efficiencies beyond 23%. To achieve even higher efficiencies, it is necessary to increase the understanding of crystallization, grain formation, and layer ripening. In this study, by a systematic variation of methylammonium iodide (MAI) concentrations, we changed the stoichiometry and thereupon the crystal growth conditions in MAPbI perovskite solar cells, prepared by a two-step hybrid evaporation-spin-coating deposition method.
View Article and Find Full Text PDFACS Appl Mater Interfaces
September 2017
The most efficient organic-inorganic perovskite solar cells (PSCs) contain the conventional n-i-p mesoscopic device architecture using a semiconducting TiO scaffold combined with a compact TiO blocking layer for selective electron transport. These devices achieve high power conversion efficiencies (15-22%) but mainly require high-temperature sintering (>450 °C), which is not possible for temperature-sensitive substrates. Thus far, comparably little effort has been spent on alternative low-temperature (<150 °C) routes to realize high-efficiency TiO-based PSCs; instead, other device architectures have been promoted for low-temperature processing.
View Article and Find Full Text PDFEnhanced absorption of near infrared light in silicon solar cells is important for achieving high conversion efficiencies while reducing the solar cell's thickness. Hexagonal gratings on the rear side of solar cells can achieve such absorption enhancement. Our wave optical simulations show photocurrent density gains of up to 3 mA/cm2 for solar cells with a thickness of 40 µm and a planar front side.
View Article and Find Full Text PDFThe procedure used in our previous publication [Opt. Express 20, 271, (2012)] to calculate how coupling to a spherical gold nanoparticle changes the upconversion luminescence of Er(3+) ions contained several errors. The errors are corrected here.
View Article and Find Full Text PDFLuminescent solar concentrators (LSC) are used in photovoltaic applications to concentrate direct and diffuse sunlight without tracking. We employed 2D FDTD simulations to investigate the concept of a photonic LSC (PLSC), where the luminescent material is embedded in a photonic crystal to mitigate the primary losses in LSCs: the escape cone and reabsorption. We obtain suppressed emission inside the photonic band gap, which can be utilized to reduce reabsorption.
View Article and Find Full Text PDFWe investigate plasmon resonances in gold nanoparticles to enhance the quantum yield of upconverting materials. For this purpose, we use a rate equation model that describes the upconversion of trivalent erbium based upconverters. Changes of the optical field acting on the upconverter and the changes to the transition probabilities of the upconverter in the proximity of a gold nanoparticle are calculated using Mie theory and exact electrodynamic theory respectively.
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