Open Access

ARTICLE

Nano-Array Solid Electrode Design for Photoelectrochemical Solar Cells

W.H. Chen¹, C.W. Hong^1,2

1 Department of Power Mechanical Engineering, National Tsing Hua University (NTHU), Hsinchu,Taiwan.
2 Email: cwhong@pme.nthu.edu.tw (Corresponding author)

Computers, Materials & Continua 2011, 21(2), 147-170. https://doi.org/10.3970/cmc.2011.021.147

Abstract

Nanorod/nanowell/nanotube arrays are effective nanotechnologies that can increase the performance of a photo-electrochemical solar cell by increasing the reaction area of the working electrode. However, the confined space due to the nano-arrays also tends to decrease the redox ion diffusivity. This paper describes computer modeling on the ionic diffusion of the active species (I-/I3-) among the nano-arrays of the working electrode material (TiO2). A three dimensional periodic boundary molecular dynamics simulation technique is employed to simulate the nano-scale transport phenomenon. Performance improvement tendency can be evaluated from the Butler-Volmer equation. Simulation results reveal that the increasing reaction area times the decreasing diffusion coefficient (due to decreasing porosity) can be optimized at an effective porosity around 0.75 using the nanotube array design. With this optimized design, the current density can be improved by 53% and the power density by 66%.

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Keywords

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