Improvement of carrier collection in Si/a-Si:H nanowire solar cells by using hybrid ITO/silver nanowires contacts

Abstract

Optoelectronic devices based on high aspect ratio nanowires bring new challenges for transparent electrodes, which can be well addressed by using hybrid structures. Here we demonstrate that a composite contact to radial junction nanowire solar cells made of a thin indium-tin oxide (ITO) layer and silver nanowires greatly improves the collection of charge carriers as compared to a single thick ITO layer by reducing the series resistance losses while improving the transparency. The optimization is performed on p-i-n solar cells comprising of dense non-vertical nanowires with a p-doped c-Si core and an ultra-thin a-Si:H absorption layer grown by plasma-enhanced chemical vapor deposition on glass substrates. The optimal hybrid contact developed in this work is demonstrated to increase the solar cell conversion efficiency from 4.3% to 6.6%.

Preparation of Indium Tin Oxide Nanowires by Using physical-vapor-transport method

“…It also can easily absorb and attenuate ultraviolet light. These characteristics make ITO widely used in fields such as optical coating [6] , microelectronic devices [1,7] , sensors [8] , display touch screens, and solar cells [9] . Recently, the research on ITO nanomaterials has attracted much attention due to the potential of developing applications in the miniaturization of sensors and high-performance optoelectronic devices [10,11] .…”

Silicon Nanowire Design for Ultrahigh Extinction by Dipole Near-Field Interaction in Transparent Solar Cells

“…Semiconductor nanowires are widely used in optoelectronic, biological, chemical, and medical fields due to the unique effects of their nanoscale on mechanical, optical, and electrical fields. − Among them, silicon nanowires (SiNWs) have been widely used in the photovoltaic field with their excellent optical properties, various preparation processes, flexible morphology control methods, and good material compatibility. − In Si solar cells, the SiNW array can achieve ultralow reflectivity in the wavelength range of 300–1100 nm, which greatly increases the light absorption of solar cells . In addition, SiNW arrays can be directly grown on transparent substrates or transferred from Si substrates to transparent media to prepare the SiNW array transparent solar cells (TSCs). ,− The SiNW array TSCs are classified according to their materials, including Si/organic hybrid, a-Si/c-Si, and c-Si solar cells. ,, Compared with thin film solar cells, the SiNW array TSCs have visible transparency and ultralow reflectivity and flexibility compared with transparent c-Si solar cells. ,− In addition, this kind of solar cell can obtain higher open circuit voltage ( V OC ) due to the strong concentrating light of a single SiNW …”