| AVS 56th International Symposium & Exhibition | |
| Electronic Materials and Processing | Tuesday Sessions |
| Session EM1+PV-TuM |
| Session: | High Efficiency and Quantum Structure Photovoltaics |
| Presenter: | M.C. Petcu, Eindhoven University of Technology, The Netherlands |
| Authors: | M.C. Petcu, Eindhoven University of Technology, The Netherlands A. Sarkar, Eindhoven University of Technology, The Netherlands M. Creatore, Eindhoven University of Technology, The Netherlands H.T. Hintzen, Eindhoven University of Technology, The Netherlands M.C.M. van de Sanden, Eindhoven University of Technology, The Netherlands |
| Correspondent: | Click to Email |
Nowadays the application of thin SiNx layers as bulk passivating and antireflection coatings for Si-based solar cells applications is considered to be a successful solution for the increase in efficiency1. A new concept to further increase the efficiency of the solar cell is based on the light conversion mechanism: according to this approach the solar spectrum can be efficiently modified by shifting the photons towards a wavelength range where the solar cell has a better or higher response2.
Recently, a novel class of rare earth (RE)- doped SiNx layers has been demonstrated to be a highly promising red-emitting conversion phosphor for white-LED applications. These materials have allowed the shifting of the emission wavelength by tuning the concentration of a specific RE element in a SiNx based crystalline matrix3. The investigation of RE-doped amorphous silicon nitride (SiNx) compounds, where the electronic properties of Si are combined with the optical properties of RE3+ ions, have been shown already potential in optoelectronics4. Therefore, parallel studies on the incorporation of a RE material in amorphous SiNx host lattices, which could be implemented in solar cells to increase the efficiency, are considered to be presently a challenge.
In this contribution the properties of europium- and samarium- doped amorphous SiNx layers are investigated. The RE-doped SiNx layers are deposited using a remote PECVD expanding thermal plasma fed with Ar/SiH4/NH3 mixtures in combination with a RE magnetron sputtering source implemented in the proximity of the substrate holder. Growth rates of the RE doped layers obtained from Spectroscopic Ellipsometry (SE) measurements were in the range 0.6-2.2 nm/s. The successful incorporation of RE in the SiNx matrix has been demonstrated by means of Rutherford Back Scattering (RBS) and X-ray Photoelectron Spectroscopy (XPS) analysis, i.e. up to 2%. Preliminary photoluminescence results point out a broad band emission in the region of 500-800 nm when excitation wavelengths of 270 nm and 320 nm have been used. The emission band observed can be attributed to Sm2+.
[1] J. Hong et al., J. Vac. Sci. Technol. B. 21 (5).
[2] C. Strümpel et al., Sol. Energ. Mat. Sol. C. 91 (2007) 238 – 249.
[3] Y. Q. Li et al., J. Alloys. and Comp. 417, 273 – 279.
[4] A. R. Zanatta, et al., J. Phys.:Condens. Matter 19 (2007) 436230.