Title :
Characterization of Structure and Growth Evolution for nc-Si:H in the Tandem Photovoltaic Device Configuration
Author :
Zhiquan Huang ; Dahal, Lila R. ; Junda, Maxwell M. ; Aryal, Puruswottam ; Marsillac, Sylvain ; Collins, Robert W. ; Podraza, Nikolas J.
Author_Institution :
Dept. of Phys. & Astron., Univ. of Toledo, Toledo, OH, USA
Abstract :
Spectroscopic ellipsometry (SE) is used to study the growth evolution of the bottom cell p-type doped and intrinsic hydrogenated silicon (Si:H) layers in p-i-n amorphous/nanocrystalline Si:H (a-Si:H/nc-Si:H) tandem photovoltaic (PV) devices. SE data collected in situ during the growth enables the identification of crystallite coalescence transitions in the surface roughness evolution, as well as the variations in optical response in the form of the complex dielectric function (ε = ε1 + iε2). The latter indicates relative amounts of the a-Si:H and nc-Si:H components during mixed-phase Si:H growth. A growth evolution diagram for the i-layer in the tandem PV device configuration is constructed. Device properties are related to p- and i-layer structure and can be understood on the basis of the growth evolution diagram.
Keywords :
amorphous semiconductors; crystallites; dielectric function; elemental semiconductors; ellipsometry; hydrogen; nanofabrication; nanostructured materials; photovoltaic effects; semiconductor growth; silicon; solar cells; surface roughness; Si:H; complex dielectric function; crystallite coalescence transitions; hydrogenated silicon; p-i-n amorphous-nanocrystalline tandem photovoltaic devices; spectroscopic ellipsometry; surface roughness; Crystalline materials; Ellipsometry; Photovoltaic cells; Silicon; Complex dielectric function spectra; growth evolution diagram; nanocrystalline silicon; photovoltaic (PV) cells; real-time spectroscopic ellipsometry;
Journal_Title :
Photovoltaics, IEEE Journal of
DOI :
10.1109/JPHOTOV.2015.2478056
