RESUMEN
We present tailor-made imprinted nanostructures for light management in liquid phase crystallized silicon thin-film solar cells providing both, increased jsc by enhanced absorption and excellent electronic material-quality with Voc-values >640mV. All superstrate textures successfully enhance light in-coupling in 10-20µm thick liquid phase crystallized silicon thin-films. Moreover, the effect of combining imprinted textures at the front side with individually optimized light trapping schemes at the rear side of the absorber layers on the optical properties is analyzed. With a silicon absorber layer thickness of 17µm maximum achievable short-circuit current density of 37.0mA/cm2 is obtained, an increase by + 1.8mA/cm2 (or 5.1%) compared to the optimized planar reference.
RESUMEN
Recently, liquid phase crystallization of thin silicon films has emerged as a candidate for thin-film photovoltaics. On 10 µm thin absorbers, wafer-equivalent morphologies and open-circuit voltages were reached, leading to 13.2% record efficiency. However, short-circuit current densities are still limited, mainly due to optical losses at the glass-silicon interface. While nano-structures at this interface have been shown to efficiently reduce reflection, up to now these textures caused a deterioration of electronic silicon material quality. Therefore, optical gains were mitigated due to recombination losses. Here, the SMooth Anti-Reflective Three-dimensional (SMART) texture is introduced to overcome this trade-off. By smoothing nanoimprinted SiO x nano-pillar arrays with spin-coated TiO x layers, light in-coupling into laser-crystallized silicon solar cells is significantly improved as successfully demonstrated in three-dimensional simulations and in experiment. At the same time, electronic silicon material quality is equivalent to that of planar references, allowing to reach V oc values above 630 mV. Furthermore, the short-circuit current density could be increased from 21.0 mA cm-2 for planar reference cells to 24.5 mA cm-2 on SMART textures, a relative increase of 18%. External quantum efficiency measurements yield an increase for wavelengths up to 700 nm compared to a state-of-the-art solar cell with 11.9% efficiency, corresponding to a j sc, EQE gain of 2.8 mA cm-2.
RESUMEN
BACKGROUND: A number of posterior approaches to the elbow have been described, which vary in the quality of the exposure and morbidity to the triceps mechanism. We describe an adapted technique, the Triceps Split and Snip, which may offer improved surgical exposure during posterior approach to the elbow. We aimed to compare the strength of the triceps repair in this approach to a more traditional approach described by Bryan and Morrey. METHODS: Sixteen pairs of cadaveric elbows were randomized by surgical group and operative side. The Triceps Split and Snip and Bryan-Morrey approaches were each performed on eight specimens, followed by repair of the triceps; the contralateral elbow served as the control. The specimens were then mounted on a material testing system and a constant velocity elongation was applied. RESULTS: The mean load to failure for the Bryan-Morrey group was 421N (range 349-536N). While the Triceps Split and Snip group was 388N (range 267-550N). The percentage ultimate strength loss was 40% for both groups. No significant difference was found in comparing the mean load to failure between the Triceps Split and Snip approach and the Bryan-Morrey approach. CONCLUSIONS: The Triceps Split and Snip approach is a technically simple approach to perform and repair, and provides excellent exposure of the elbow and distal humerus. The tensile strength of the triceps repair following this approach is equivalent to that of the Bryan-Morrey approach.