Plasmon-Enhanced Light Absorption In GaAs Nanowire Array Solar Cells

High-efficiency photovoltaic devices has been a hot topic to solve the problem of future energy,but the high cost of solar cell has became the main obstacle of the solar cells been widely used.Solar cells compound of III-V semiconductor nanowires arrays is a popular research direction of new generation of solar cells.Nanowires unique one-dimensional structure makes the synthesis of axial/radial p-n junction and heterostructures in a single nanowire possible.Simple nanowire arrays p-n junction solar cells can reduce the cost of solar cells,but also far away from people’s expectations.In order to further reduce the cost of solar cells,this paper attached metal nanoparticles on III-V nanowires faces to excitation surface plasmon,to improve the light absorption of III-V nanowires array,and improve the conversion efficiency of the III-V semiconductor nanowires array solar cells,reduce the cost of nanowire array solar cells.we propose a plasmon-enhanced solar cell structure based on a GaAs nanowire array decorated with metal nanoparticles,then we do simulation experiment to study and analysis the local surface plasomon influence to the optical and electrical properties of the nanowire arrays solar cells.The main research results as follows:Firstly,study III-V semiconductor nanowires array solar cells,and study the surface plasmon characteristics,and then propose a plasmon-enhanced solar cell structure based on a GaAs nanowire array decorated with metal nanoparticles to combine nanowires array with plasmon to catch light to greatly increase the photoelectric conversion efficiency of solar cells with low density nanowires,reduce the cost of solar cells.Secondly,based on the finite difference time domain method,using FDTD Solution simulation software to simulate and analysis the optical performance of solar cells with new structure,including the optical field distribution in the nanowire arrays,the influence of metal nanoparticles to nanowires array light absorption,light reflectivity of nanowires array and so on.Compare the light absorption result of optimized nanowires array with and without metal particles,we can find,the introduction of metal nanoparticles in the nanowire arrays,can significantly improve the near band gap incident light capture and absorption ability of solar cell with low nanowire density.Thirdly,based on the FDTD Solution simulation result,we study solar cells’ electrical characteristics with Sentaurus simulation software.Results show that through continuous optimization of structural parameters of the nanowire arrays and metal nanoparticles,the photoelectric conversion efficiency can be increased by 22%when the D/P ratio(diameter and period ratio)of nanowire arrays is 0.3.Change the incident Angle of incident light,the metal particle shape and distribution study the further photovoltaic characteristics of this solar cells.The results show that:(1)in the case of oblique incidence,the introduction of plasmon also can significantly improve the photoelectric conversion efficiency of nanowire arrays solar cells.(2)the metal particles in the nanowires sidewall distribution more uniform,nanowire arrays of solar cell performance is better.Fourthly,according to the laboratory conditions,carries on the experimental study of solar cell device.The J-V curves of solar cells with diode characteristics,but the nanowires doping concentration and the influence of the nanowires surface depletion layer lead to a large series resistance of the solar cell device.Due to the bending p-n interface lead to the leakage current of axial p-n junction solar cell increases quickly with the increase of the reverse bias.The research of III-V nanowire arrays of solar cells is a great significancehas to the new generation of solar cells in further reduce the cost of materials.