Publications Repository - Helmholtz-Zentrum Dresden-Rossendorf
1 PublicationNetworks of Si nanowires in SiO2 for solar cells
Heinig, K.-H.; Schmidt, B.; Mücklich, A.; Liedke, B.; Kelling, J.; Friedrich, D.; Hauschild, D.; Stegemann, K.-H.; Keles, U.; Bulutay, C.; Aydinli, A.
Abstract
In Si-based thin film solar cells the a-Si:H or nanocrystalline absorber layer can be replaced by a network of Si nanowires (Si nanosponge) embedded in SiO2[1]. The Si nanosponge is formed by spinodal decomposition of metastable SiO layers which have been deposited by different techniques, sputtering, CVD and e-beam evaporation. The spinodal decomposition has been activated by Rapid Thermal Processing and laser annealing. When the volume fraction of Si exceeds ~30% after the phase separation SiOx-->0.5SiO2+(1-0.5x) Si, then Si forms a nanowire network. Energy-Filtered Transmission Electron Microscopy (EFTEM) studies show that nanowires have diameters of a few nanometers with a narrow distribution. This is in excellent agreement with large-scale simulations based on bit-coded kinetic Monte-Carlo. There is a considerable Si band gap widening due to quantum confinement in the nanowire network. As the wire diameter coarsens with time of heat treatment like d~t0.33, the band gap of the Si nanosponge can be optimized for solar cell application. Using an atomistic pseudopotential method, the band gap of sponges have been studied. Finally it will be shown that up-scaling of the nanotechnology described above to large-scale PV cell production is under way by industrial partners. [1] BMBF-TÜBITAK project “RainbowEnergy”, coordinators K.-H. Heinig and A. Aydinli
Keywords: nanocomposite; silicon; silica; sponge; solar cell; sputter deposition; laser annealing; band gap; atomistic simulations
Involved research facilities
- Ion Beam Center DOI: 10.17815/jlsrf-3-159
Related publications
- DOI: 10.17815/jlsrf-3-159 is cited by this (Id 18330) publication
-
Lecture (Conference)
E-MRS Spring Meeting 2012, Symp. A, 14.-18.05.2012, Strasbourg, Frankreich
Permalink: https://www.hzdr.de/publications/Publ-18330
Years: 2023 2022 2021 2020 2019 2018 2017 2016 2015