SiNW/C@Pt Arrays for High-Efficiency Counter Electrodes in Dye-Sensitized Solar Cells

Junhee Kim,Sanghoon Jung,Soo Min Kim,Yoonkap Kim,Chanyong Lee,Yongseok Jun,Donghwan Kim,Han-Jung Kim

doi:10.3390/en13010139

Abstract

Modern energy needs and the pressing issue of environmental sustainability have driven many research groups to focus on energy-generation devices made from novel nanomaterials. We have prepared platinum nanoparticle-decorated silicon nanowire/carbon core–shell nanomaterials (SiNW/C@Pt). The processing steps are relatively simple, including wet chemical etching to form the silicon nanowires (SiNWs), chemical vapor deposition to form the carbon shell, and drop-casting and thermal treatment to embed platinum nanoparticles (Pt NPs). This nanomaterial was then tested as the counter electrode (CE) in dye-sensitized solar cells (DSSCs). SiNW/C@Pt shows potential as a good electrocatalyst based on material characterization data from Raman spectroscopy and X-ray photoelectron spectroscopy (XPS). Raman spectroscopy shows that the surface reactivity of the SiNW/C is increased by the decoration of Pt NPs. These data also show that the carbon shell included both graphitic (sp 2 hybridization) and defective (sp 3 hybridization) phases of carbon. We achieved the minimum charge-transfer resistance of 0.025 Ω · cm 2 and the maximum efficiency of 9.46% with a symmetric dummy cell and DSSC device fabricated from the SiNW/C@Pt CEs, respectively.

Highlights

Nanowires have been studied extensively over the past decade due to their versatility and applications as promising building components in next-generation nanoscale devices like electrochemical batteries [1,2,3,4], biosensors [5,6,7], light-emitting diodes (LEDs) [8,9], transparent conducting electrodes [10], solar cells [11,12], and metamaterials [13,14]
silicon nanowires (SiNWs) arrays were formed on Si substrates using metal-assisted chemical etching (MaCE)
This study demonstrated methods for the preparation and photovoltaic application of a novel nanomaterial, a silicon nanowire/carbon core–shell nanomaterial with platinum nanoparticles (SiNW/C@Pt)

Summary

Introduction

Nanowires have been studied extensively over the past decade due to their versatility and applications as promising building components in next-generation nanoscale devices like electrochemical batteries [1,2,3,4], biosensors [5,6,7], light-emitting diodes (LEDs) [8,9], transparent conducting electrodes [10], solar cells [11,12], and metamaterials [13,14]. Recent efforts have focused on improving the characteristics of such materials with core–shell nanowires. Sanming et al synthesized hierarchical NiCo2 O4 @NiWO4 core–shell nanowire arrays and found that these perform excellently as supercapacitors [4]. Li4 Ti5 O12 (N-LTO) with TiC/C skeletons for ultrafast Li ion storage. This material demonstrated outstanding rates and cycling stability [15]. Core–shell nanowires can be used as electrocatalysts. Bai et al synthesized Ag2 S@MoS2 core–shell nanowires with different loadings of MoS2 to be used in producing hydrogen via Energies 2020, 13, 139; doi:10.3390/en13010139 www.mdpi.com/journal/energies

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Results

Conclusion