3D structured backside electrode intended for perovskite photoelectric converters: a novel approach

Abstract

This work explores the integration of three-dimensionally (3D) structured rear electrode intended for perovskite solar cells to enhance light management and mechanical stability, addressing limitations as inner light distribution and durability that hinder the performance of these thin-film devices. The motivation for this research arises from the need for improved light trapping and robust electrode structures in flexible and wearable solar cell applications. 3D electrodes were fabricated using grayscale lithography, enabling precise control over surface topography and subsequent aluminum metallization to create a strongly reflective layer. The resulting electrodes were characterized for sheet resistance, reflectance of light with a peak emission wavelength of 700 nm and irradiance of up to 4 mW/cm², and mechanical stability at 10 000 bending cycles. Results demonstrate that the 3D structured electrodes exhibit enhanced reflectance compared to flat electrodes, which is a precondition for improved light trapping. Furthermore, they show improved electrical performance, as well as mechanical stability under bending, maintaining higher reflectance and lower sheet resistance increase compared to flat electrodes. These findings suggest that 3D structured rear electrodes fabricated by grayscale lithography offer a promising approach for improving the efficiency and durability of perovskite solar cells, particularly for flexible and wearable applications. The power conversion efficiency (PCE) increased from 17.7% for a flat electrode to 21.4% for a 3D patterned. Moreover, 3D patterned layers exhibited only 12.5% drop in their reflectance after multiple bending, while the flat electrodes exhibited a 19%.

Keywords

Rear electrodes / Grayscale photolithography / 3D patterns / Perovskite solar cells

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Funding

Bulgarian National Science Fund(КP-06-Н87/1)

RIGHTS & PERMISSIONS

The Author(s), under exclusive licence to the International Society of Energy and Environmental Science