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Hydrothermally synthesized disordered ZnO nanowires were conformally coated with a-Si:H thinfilms to fabricate three dimensional hybrid nanowire/thin-film structures. The a-Si:H layer formed a radial junction p-i-n diode solar cell around the ZnO nanowire. The cylindrical hybrid solar cells enhanced light scattering throughout the UV-visible-NIR spectrum (300 nm-800 nm) resulting in a 22% increase in short-circuit current density compared to the reference planar p-i-n device. A fill factor of 69% and a total power conversion efficiency of 6.5% were achieved with the hybrid nanowire solar cells using a spin-on indium tin oxide nanoparticle suspension as the top contact. [ABSTRACT FROM AUTHOR]

In this work, the impact of two different growth modes on the efficiency of an amorphous thin film solar cell comprising randomly textured interfaces is investigated. The two modes are the commonly used conformal growth which assumes identical textured interfaces and the isotropic growth, in which deposited material grows in the direction of the local surface normal. In the latter, the texture's morphology can change significantly. The rivalling impact of these two growth modes on the solar cell absorption is not yet fully understood. Here, we show that the efficiency of a solar cell crucially depends on the growth mode. In different size regimes, they may outperform each other with regard to efficiency by almost 15%. The insights gained by this study will guide experimentalists in the future in selecting the optimised growth mode. [ABSTRACT FROM AUTHOR]

The influence of nanotextured metallic back contacts on light trapping and plasmonic losses of amorphous silicon solar cells was investigated. The optical losses of the back contact are determined by the texture of the metallic back contact and the dielectric constant of the interlayer between the solar cell and the metal back contact. The investigations show that the optical losses are highest if nano features are present at the back contact, while the texture of the front contact which propagates through the layer stack exhibits only a minor effect on the optical losses. [ABSTRACT FROM AUTHOR]

The light propagation in multiscale textured thin film silicon solar cells is studied experimentally and numerically. The short circuit current and energy conversion efficiency of multiscale textured amorphous silicon thin film solar cells are increased compared to nanoscale textured substrates. A gain of the short circuit current of 1.3 mA/cm 2 is achieved for the multiscale textured solar cell, resulting in short circuit current densities of 16.8 mA/cm 2 and energy conversion efficiency of 10.7%. The light propagation in the solar cells is determined by Finite Difference Time Domain simulations in three dimensions using realistic interface morphologies. The realistic interface morphologies of solar cells are calculated by 3D algorithms. The optical simulations reveal that the interface morphology of the back reflector of the multiscale textured solar cell has a distinct influence on the short circuit current and quantum efficiency. By tuning the optical losses of the metal back reflector, the short circuit current can be increased beyond 18 mA/cm 2 . [ABSTRACT FROM AUTHOR]

Abstract: The influence of the interface morphologies on amorphous silicon thin-film solar cells prepared on randomly textured substrates was studied. A simple three-dimensional geometrical model was developed to describe the surface morphology of amorphous silicon films and thin-film solar cells. The simulated surface morphologies are confirmed by experimental measurements. A detailed understanding of the interface morphologies is required to gain insights in the light-trapping of silicon thin-film solar cells on randomly textured substrates and derive strategies to improve the light-trapping properties. The morphology of amorphous silicon solar cell layers is calculated by using atomic force microscope scans of the randomly textured substrates and the thickness of layers as input data. The influence of the interface morphologies on the surface roughness, average film thickness and size of surface textures is investigated. Finally the influence of these parameters on the light-trapping and optical losses is discussed. [Copyright &y& Elsevier]