Numerical Approach to the Plasmonic Enhancement of Cs2AgBiBr6 Perovskite-Based Solar Cell by Embedding Metallic Nanosphere

Abstract

Lead-free Cs2AgBiBr6 perovskites have emerged as a promising, non-toxic, and eco-friendly photovoltaic material with high structural stability and a long lifetime of carrier recombination. However, the poor-light harvesting capability of lead-free Cs2AgBiBr6 perovskites due to the large indirect band gap is a critical factor restricting the improvement of its power conversion efficiency, and little information is available about it. Therefore, this study focused on the plasmonic approach, embedded metallic nanospheres in Cs2AgBiBr6 perovskite solar cells, and quantitatively investigated their light-harvesting capability via finite-difference time-domain method. Gold and palladium were selected as metallic nanospheres and embedded in a 600 nm thick-Cs2AgBiBr6 perovskite layer-based solar cell. Performances, including short-circuit current density, were calculated by tuning the radius of metallic nanospheres. Compared to the reference devices with a short-circuit current density of 14.23 mA/cm2, when a gold metallic nanosphere with a radius of 140 nm was embedded, the maximum current density was improved by about 1.6 times to 22.8 mA/cm2. On the other hand, when a palladium metallic nanosphere with the same radius was embedded, the maximum current density was improved by about 1.8 times to 25.8 mA/cm2.

Numerical Study on Overcoming the Light-Harvesting Limitation of Lead-Free Cs2AgBiBr6 Double Perovskite Solar Cell Using Moth-Eye Broadband Antireflection Layer

“…Figure 1b shows the two-dimensional cross-sectional view of the simulation process. All simulations were processed based on the optimized device condition with reference to previous literature, except for the Au thickness condition [18]. The z span of a parabolic cone with an x span of 500 nm, which imitated the moth-eye AR layer, was scaled from 50 to 500 nm at an interval of 50 nm.…”

“…As one of the double perovskite materials with this structure, Cs 2 AgBiBr 6 double perovskites have emerged as promising candidates with a 3D structure, excellent thermal stability, long carrier lifetime, a relatively small carrier effective mass, and low toxicity [13,16]. Moreover, superior defect tolerance and multi-functionality properties make Cs 2 AgBiBr 6 double perovskites potentially excellent candidates for next-generation perovskite photovoltaics [17,18]. However, the low power conversion efficiency (PCE ≈ 3%), due to a large indirect band gap (≈2 eV) and poor light-harvesting capability [19], is the main limitation of Cs 2 AgBiBr 6 double perovskites in the manufacturing of solar cells.…”

“…Herein, a numerical study on the performance improvements in Cs 2 AgBiBr 6 double perovskite-based solar cells with the parabola-shaped moth-eye broadband antireflection layer has been performed via FDTD simulation [18,32,33]. We selected aluminum oxide (Al 2 O 3 ; n: 1.77), zinc oxide (ZnO; n: 1.9), magnesium fluoride (MgF 2 ; n: 1.38), and silicon dioxide (SiO 2 ; n: 1.46) as an AR layer material, which have suitable refractive indices and excellent antireflecting roles in real fabrication, have been selected for this simulation [34][35][36][37].…”