Open AccessAdvancing tandem solar cells by spectrally selective multilayer intermediate reflectors
Author(s) -
André Hoffmann,
Ulrich W. Paetzold,
Chao Zhang,
Tsvetelina Merdzhanova,
Andreas Lambertz,
Carolin Ulbrich,
Karsten Bittkau,
Uwe Rau
Publication year - 2014
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.22.0a1270
Subject(s) - tandem , materials science , optoelectronics , silicon , optics , amorphous silicon , solar cell , plasmonic solar cell , reflector (photography) , polymer solar cell , crystalline silicon , doping , physics , light source , composite material
Thin-film silicon tandem solar cells are composed of an amorphous silicon top cell and a microcrystalline silicon bottom cell, stacked and connected in series. In order to match the photocurrents of the top cell and the bottom cell, a proper photon management is required. Up to date, single-layer intermediate reflectors of limited spectral selectivity are applied to match the photocurrents of the top and the bottom cell. In this paper, we design and prototype multilayer intermediate reflectors based on aluminum doped zinc oxide and doped microcrystalline silicon oxide with a spectrally selective reflectance allowing for improved current matching and an overall increase of the charge carrier generation. The intermediate reflectors are successfully integrated into state-of-the-art tandem solar cells resulting in an increase of overall short-circuit current density by 0.7 mA/cm(2) in comparison to a tandem solar cell with the standard single-layer intermediate reflector.