ABSTRACT
ß-delayed one-proton emissions of ^{22}Si, the lightest nucleus with an isospin projection T_{z}=-3, are studied with a silicon array surrounded by high-purity germanium detectors. Properties of ß-decay branches and the reduced transition probabilities for the transitions to the low-lying states of ^{22}Al are determined. Compared to the mirror ß decay of ^{22}O, the largest value of mirror asymmetry in low-lying states by far, with δ=209(96), is found in the transition to the first 1^{+} excited state. Shell-model calculation with isospin-nonconserving forces, including the T=1, J=2, 3 interaction related to the s_{1/2} orbit that introduces explicitly the isospin-symmetry breaking force and describes the loosely bound nature of the wave functions of the s_{1/2} orbit, can reproduce the observed data well and consistently explain the observation that a large δ value occurs for the first but not for the second 1^{+} excited state of ^{22}Al. Our results, while supporting the proton-halo structure in ^{22}Al, might provide another means to identify halo nuclei.
ABSTRACT
We report the realization of both excellent optical and electrical properties of nanostructured multicrystalline silicon solar cells by a simple and industrially compatible technique of surface morphology modification. The nanostructures are prepared by Ag-catalyzed chemical etching and subsequent NaOH treatment with controllable geometrical parameters and surface area enhancement ratio. We have examined in detail the influence of different surface area enhancement ratios on reflectance, carrier recombination characteristics and cell performance. By conducting a quantitative analysis of these factors, we have successfully demonstrated a higher-than-traditional output performance of nanostructured multicrystalline silicon solar cells with a low average reflectance of 4.93%, a low effective surface recombination velocity of 6.59 m s(-1), and a certified conversion efficiency of 17.75% on large size (156 × 156 mm(2)) silicon cells, which is â¼0.3% higher than the acid textured counterparts. The present work opens a potential prospect for the mass production of nanostructured solar cells with improved efficiencies.