J Am Chem Soc 2012, 134:3419–3428.CrossRef 32. Wang YD, Wu MX, Lin X, Shi ZC, Hagfeldt A, Ma TL: Several highly efficient catalysts for Pt-free and FTO-free counter electrodes of dye-sensitized ZD1839 clinical trial solar cells. J Mater Chem

2012, 22:4009–4014.CrossRef Competing interests The MK0683 supplier Authors declare that they have no competing interests. Authors’ contributions JK carried out the experiments, characterization, and acquisition of data. ZJZ participated in the designing of the experiments, experiment analysis, interpretation of data, and language modification. ML and WHZ carried out the sample preparation and measurements. SJY, RYY, and YZ participated in the discussion. SXW is the investigator who helped in the analysis and interpretation of data, drafting of the manuscript, and revisions. All authors read and approved the final manuscript.”
“Background Silicon nanowires (SiNWs) attract significant attention because of their potential MX69 research buy applications in many fields like sensors, transistors, lithium batteries, diodes, and photovoltaics [1–5]. Particularly, they can be applied on silicon solar cells as an antireflection coating, due to low average reflectance values [6, 7]. Several synthesis methods have been used to

fabricate SiNWs including chemical vapor deposition [8], laser ablation [9], thermal evaporation, and solution methods [10–12]. Among these synthesis methods, wet chemical etching has been frequently used to prepare SiNWs. Metal-assisted wet chemical etching is advantageous click here for achieving SiNWs with controlled diameter,

length, spacing, and density, avoiding expensive and low-throughput usual lithographic processes [13]. Recently, it has been shown that a silicon nanowire antireflection coating (ARC) prepared by metal-assisted wet chemical etching is a near-perfect antireflection coating [14]. The superior antireflection property of the nanowire surface is attributed to three reasons: huge surface area of SiNWs, rough surface morphology which leads to strong light scattering as well as absorption, and graded refractive index profile between air and SiNWs that closely implies a multilayer antireflection coating [6, 14, 15]. Some other properties of SiNWs, for example, crystal ordination, good doping level, and excellent uniformity, imply appropriate utilization of SiNWs in silicon solar cells. Despite all these features, the maximum efficiency of planar solar cells using SiNW ARC does not exceed 10%. This low efficiency is attributed to many factors. One of the most important is the surface recombination velocity which strongly increases when using SiNW ARC, due to the large surface area [16, 17]. It is necessary, therefore, to passivate the SiNW surface, minimizing the surface states [18].