Authors’ contributions LCC wrote the paper, designed the experiments, and analyzed the data. WFT prepared the samples and did all the measurements. Both authors read and approved the final manuscript.”
“Background Over the past decades, a great deal of efforts has been carried out to improve the conversion efficiency of crystalline silicon (c-Si) solar cells, which occupy most of the solar cell market [1, 2]. To achieve a high-efficiency c-Si solar cell, antireflective layers/structures are inevitably necessary for enhancing the transmission of the sunlight into the solar cells by suppressing surface reflection, which is caused by the refractive index difference at the air/c-Si interface.
check details Recently, subwavelength-scale nanostructures have attracted considerable attention as a promising antireflective structure to minimize unwanted reflection losses, due to their long-term stability, and broadband and omnidirectional antireflection properties [3–10]. To produce subwavelength-scale Si nanostructures, a dry etching method using nanoscale mask patterns has been commonly employed [7–10]. However, this method is complex, expensive, selleck kinase inhibitor and inadequate for mass BKM120 production and may cause damage to the crystal structure
and surface morphology due to high-energy ions . In recent years, metal-assisted chemical etching (MaCE), based on the strong catalytic activity of metal in an aqueous solution composed of HF and an oxidant, has attracted great interest as a method for fabricating Si nanostructures for electronic and optoelectronic devices [2, 6, 12–18]. This is a simple, fast, cost-effective, and high-throughput method for fabricating various Si nanostructures without any sophisticated equipment or ion-induced surface damages. The antireflection properties of nanostructures
are strongly correlated with their dimensions and etching profiles [4–8], which can be controlled by adjusting the pattern of the metal catalyst  and etching conditions, such as etching time, etchant concentration, and etching Y-27632 2HCl temperature for MaCE [6, 12–16]. However, the antireflection characteristics of Si nanostructures, which take into account the etchant concentration and etching temperature of MaCE, have been less explored. Therefore, it is meaningful to investigate the optimum Si MaCE condition to achieve desirable antireflective Si nanostructures for practical solar cell applications. Another aspect of this parametric study is that we could confirm the self-cleaning effects of the fabricated structures as well as the optical properties . In this paper, we investigated the influence of Si MaCE conditions including the concentration of HNO3 (i.e., oxidant), HF, deionized (DI) water, and etching temperature on the morphologies and optical properties of Si nanostructures for obtaining the most appropriate antireflective Si nanostructures with self-cleaning function for solar cell applications.