Structural variations of Si1−x C x and their light absorption controllability
1 KIER-UNIST Advanced Center for Energy, Korea Institute of Energy Research, 152 Gajeong-ro, Yuseong-gu, Daejeon, 305-343, South Korea
2 Department of Physics, Chungnam National University, Yuseong-gu, Daejeon, 305-764, South Korea
3 Department of Electrical, Electronic, and Control Engineering, Hankyong National University, Anseong-si, Gyeonggi-do, 456-749, South Korea
Nanoscale Research Letters 2012, 7:503 doi:10.1186/1556-276X-7-503Published: 6 September 2012
The emergence of third-generation photovoltaics based on Si relies on tunable bandgap materials with embedded nanocrystalline Si. One of the most promising approaches is based on the mixed-phase Si1 − xCx. We have investigated the light absorption controllability of nanocrystalline Si-embedded Si1 − xCx produced by thermal annealing of the Si-rich Si1 − xCx and composition-modulated superlattice structure. In addition, stoichiometric SiC was also investigated to comparatively analyze the characteristic differences. As a result, it was found that stoichiometric changes of the matrix material and incorporation of oxygen play key roles in light absorption controllability. Based on the results of this work and literature, a design strategy of nanocrystalline Si-embedded absorber materials for third-generation photovoltaics is discussed.