Performance optimization of flexible a-Si:H solar cells with nanotextured plasmonic substrate by tuning the thickness of oxide spacer layer. (January 2015) - Xiao, Huapeng
Abstract: Plasmonic thin film solar cells deposited on periodically textured photonic crystal substrates have been extensively studied since the substantially enhanced light absorption. The reduction of parasitic absorption losses in the metal and spacer layers becomes one of the key issues to achieve high efficiency solar cells. Herein, plasmonic amorphous silicon (a-Si:H) flexible thin film solar cells with different thickness of oxide spacer layers are systematically investigated. An increase of the spacer layer thickness leads to an evolution in surface morphology of AZO and final devices. More intriguingly, the increase of spacer layer thickness reduces the absorption in Ag layer while induces more absorption in spacer layer. The highest light absorption in silicon layer is observed as applying 100 nm spacer layer, which is further verified by electrical measurements. Our observations demonstrate a versatile and convenient route towards rational design of light harvesting nanostructure for high performance plasmonic solar cells based on a broad range of materials. Graphical abstract: Highlights: Amorphous silicon thin film solar cells are constructed on patterned substrates. The devices properties are studied as a function of spacer layer thickness. An increase of spacer layer thickness reduces the absorption loss of Ag layer. The device with 100 nm spacer layer confines more incident light in silicon layer.