Embedded Metal Electrode for Organic–Inorganic Hybrid Nanowire Solar Cells

Abstract

We demonstrate here an embedded metal electrode for highly efficient organic-inorganic hybrid nanowire solar cells. The electrode proposed here is an effective alternative to the conventional bus and finger electrode which leads to a localized short circuit at a direct Si/metal contact and has a poor collection efficiency due to a nonoptimized electrode design. In our design, a Ag/SiO electrode is embedded into a Si substrate while being positioned between Si nanowire arrays underneath poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS), facilitating suppressed recombination at the Si/Ag interface and notable improvements in the fabrication reproducibility. With an optimized microgrid electrode, our 1 cm hybrid solar cells exhibit a power conversion efficiency of up to 16.1% with an open-circuit voltage of 607 mV and a short circuit current density of 34.0 mA/cm. This power conversion efficiency is more than twice as high as that of solar cells using a conventional electrode (8.0%). The microgrid electrode significantly minimizes the optical and electrical losses. This reproducibly yields a superior quantum efficiency of 99% at the main solar spectrum wavelength of 600 nm. In particular, our solar cells exhibit a significant increase in the fill factor of 78.3% compared to that of a conventional electrode (61.4%); this is because of the drastic reduction in the metal/contact resistance of the 1 μm-thick Ag electrode. Hence, the use of our embedded microgrid electrode in the construction of an ideal carrier collection path presents an opportunity in the development of highly efficient organic-inorganic hybrid solar cells.

High‐Performance, Micrometer Thick/Conformal, Transparent Metal‐Network Electrodes for Flexible and Curved Electronic Devices

“…Transparent conducting electrodes have drawn great attention in many optoelectronics applications, such as solar cells, flat panel displays, and touch panels . Indium tin oxide (ITO) films have been the most dominant transparent conducting electrodes due to their high transparency.…”

Nanowires for High-Efficiency, Low-Cost Solar Photovoltaics

“…This insertion layer also enhanced the V oc from 0.52 to 0.54 V, and an FF from 66.4 to 69.5%. Um et al fabricated Si NW/PEDOT:PSS solar cells [164]. In their design, a Ag/SiO 2 electrode was embedded into the Si substrate and positioned between Si NW arrays underneath PEDOT:PSS, which can facilitate suppressing recombinations at the Si-Ag interface and notably improve the fabrication reproducibility.…”

“…This solar cell had an efficiency of 11.48%, which was higher than the planar solar cells (6.16~7.59%) and the micropyramid solar cells without NWs (10.37~10.96%). At present, the polymer/NW hybrid solar cell has reached an efficiency of well over 10% [164,166]. However, these high-efficiency hybrid solar cells were using top-down etched NWs [167,168].…”

Plasmon‐Enhanced Silicon Nanowire Array‐Based Hybrid Heterojunction Solar Cells

“…[16][17][18][19] Recently it has been reported that efficiencies as high as 16% can be obtained for Si nanowires/PEDOT: PSS hybrid heterojunction solar cells using embedded metal micro grid electrode. [20] Other reports mention using different materials like DMSO, IPA, SDS mixed in various conditions (for example molecular weights and ratios, temperature, sonication, stirring, etc.) with PEDOT:PSS to increase the conductivity of the PEDOT:PSS layer.…”