Search results

Filter

Filetype

Your search for "*" yielded 548558 hits

Diffusion length of photo-generated charge carriers in layers and powders of CH3NH3PbI3 perovskite

The diffusion or transport lengths of photo-generated charge carriers in CH3NH3PbI3 layers (thickness up to 1 μm) and powders have been directly measured with high accuracy by modulated surface photovoltage after Goodman. The values of the diffusion lengths of photo-generated charge carriers ranged from 200 nm to tenths of μm. In thin CH3NH3PbI3 layers, the transport lengths corresponded to the la

Transient response of organo-metal-halide solar cells analyzed by time-resolved current-voltage measurements

The determination of the power conversion efficiency of solar cells based on organo-metal-halides is subject to an ongoing debate. As solar cell devices may exhibit very slow transient response, current-voltage scans in different directions may not be congruent, which is an effect often referred to as hysteresis. We here discuss time-resolved current-voltage measurements as a means to evaluate app

Hole transporting dye as light harvesting antenna in dye-sensitized TiO2 hybrid solar cells

We herein demonstrate the viability of utilizing the hole transporting medium of solidstate dye-sensitized solar cells for light harvesting. When using a hole transporting dye (HTD) in addition to an interface dye (ID) bound to the surface of the mesoporous metal oxide scaffold, both are shown to contribute to the photocurrent. Efficient energy transfer (ET) from the HTD to the ID was accomplished

Semi-transparent perovskite solar cells for tandems with silicon and CIGS

A promising approach for upgrading the performance of an established low-bandgap solar technology without adding much cost is to deposit a high bandgap polycrystalline semiconductor on top to make a tandem solar cell. We use a transparent silver nanowire electrode on perovskite solar cells to achieve a semi-transparent device. We place the semi-transparent cell in a mechanically-stacked tandem con

Chloride in lead chloride-derived organo-metal halides for perovskite-absorber solar cells

Organo-metal halide perovskites are an intriguing class of materials that have recently been explored for their potential in solar energy conversion. Within a very short period of intensive research, highly efficient solar cell devices have been demonstrated. One of the heavily debated questions in this new field of research concerns the role of chlorine in solution-processed samples utilizing lea

Hysteresis and transient behavior in current-voltage measurements of hybrid-perovskite absorber solar cells

Hybrid organo-metal halide perovskites are an exciting new class of solar absorber materials and have exhibited a rapid increase in solar cell efficiencies throughout the past two years to over 17% in both meso-structured and thin-film device architectures. We observe slow transient effects causing hysteresis in the current-voltage characterization of these devices that can lead to an over- or und

Purification of sucrose in sugar beet molasses by utilizing ceramic nanofiltration and ultrafiltration membranes

Molasses is a sugar mill by-product with low value that today is used primarily for animal feed. However, molasses contains large amounts of sucrose which, if purified, could be used for other purposes. In this study, purification by membrane filtration using ceramic tubular ultrafiltration (UF) and nanofiltration (NF) was examined. NF purifies sucrose by removing small compounds, whereas UF remov

Pretreatment for biorefineries : A review of common methods for efficient utilisation of lignocellulosic materials

The implementation of biorefineries based on lignocellulosic materials as an alternative to fossil-based refineries calls for efficient methods for fractionation and recovery of the products. The focus for the biorefinery concept for utilisation of biomass has shifted, from design of more or less energy-driven biorefineries, to much more versatile facilities where chemicals and energy carriers can