Discrete Optical Field Manipulation by Ag-Al Bilayer Gratings for Broadband Absorption Enhancement in Thin-Film Solar Cells
- 272 Downloads
Plasmonic gratings have been widely used for light harvesting in thin-film solar cells (TFSCs). However, the detrimental parasitic metal absorption loss limits the actual light absorption in the active layer and reduces the power conversion efficiency. In this paper, it is found that the localized surface plasmon resonance (LSPR) used to increase long-wavelength light absorption has significant field concentration around the bottom corners of metal gratings, but the field distribution for the short-wavelength absorption band localizes around the top corners of gratings. Due to the differences between the spatial field distributions and the related mechanisms of metal loss, discrete optical field manipulation is proposed to suppress the ohmic loss mainly associated with LSPR and the interband transition loss associated with metal materials by using Ag-Al bilayer gratings, where Ag has a small absorption coefficient and Al has a high plasmon frequency. Fifteen to forty percent improvements of photocurrents in TFSCs with Ag-Al bilayer gratings are observed in simulation compared to the ones with single-layer metal gratings. This combined metal nanostructure scheme suppresses the loss issue of metal and extends the application potential of plasmonic light-harvesting techniques.
KeywordsSurface plasmon Grating Thin-film solar cells
This work was supported by the grants from the National Natural Science Foundation of China (Nos. 11604367, 11774099, 11774383, and 61574158), the National Key Research and Development Program of China (No. 2016YFB0402501), the Key Frontier Scientific Research Program of the Chinese Academy of Sciences (No. QYZDB-SSW-JSC014), the Natural Science Foundation of Jiangsu Province (No. BK20150369), and the Suzhou Science and Technology Development Program Foundation (No. SYG201529).
- 11.Yang L, Mo L, Okuno Y et al (2013) Optimal design of ultra-broadband, omnidirectional, and polarization-insensitive amorphous silicon solar cells with a core-shell nanograting structure. Prog Photovolt Res Appl 21(5):1077–1086Google Scholar
- 15.Ren X, Cheng J, Zhang S, Li X, Rao T, Huo L, Hou J, Choy WCH (2016) High efficiency organic solar cells achieved by the simultaneous plasmon-optical and plasmon-electrical effects from plasmonic asymmetric modes of gold nanostars. Small 12(37):5200–5207. https://doi.org/10.1002/smll.201601949 CrossRefPubMedGoogle Scholar
- 21.Jovanov V, Moulin E, Haug FJ, Tamang A, Bali SIH, Ballif C, Knipp D (2017) From randomly self-textured substrates to highly efficient thin film solar cells: influence of geometric interface engineering on light trapping, plasmonic losses and charge extraction. Sol Energy Mater Sol Cells 160:141–148. https://doi.org/10.1016/j.solmat.2016.10.005 CrossRefGoogle Scholar
- 41.Chen X, Gu M (2016) An efficiency breakthrough in perovskite solar cells realized by Al-coated Cu nanoparticles[C]//Laser Science. Optical Society of America: JTh2A. 145Google Scholar