Broad-Band-Enhanced Plasmonic Perovskite Solar Cells with Irregular Silver Nanomaterials

The localized surface plasmon resonance (LSPR) from noble metal nanomaterials (NMs) is a promising solution to approach the theoretical efficiency for photovoltaic devices. However, the plasmon resonance of metal NMs with particular shapes and sizes can only be excited within narrow spectral ranges, which can hardly cover the broad-band solar spectrum. To address this issue, in this article, Ag NMs with irregular shapes and sizes are synthesized and embedded in the electron transport layer of perovskite solar cells. With the outstanding conductivity of Ag NMs, the series resistance and charge transfer resistance of the devices are dramatically decreased. The Ag NMs with larger size could enhance the light-trapping of the devices owing to the far-field light scattering effect. The near-field enhancement by LSPR of Ag NMs with a small size mainly contributes to the promotion of carrier transport and extraction. As a result, broad-band improvements in photovoltaic performance are achieved due to the significant enhancement of light absorption and electrical features. The highest power conversion efficiency of the perovskite solar cells increases from 19.52 to 22.42% after the incorporation of Ag NMs.