TY - JOUR
T1 - All-silicon tandem solar cells
T2 - practical limits for energy conversion and possible routes for improvement
AU - Jia, Xuguang
AU - Puthen-Veettil, Binesh
AU - Xia, Hongze
AU - Yang, Terry Chien-Jen
AU - Lin, Ziyun
AU - Zhang, Tian
AU - Wu, Lingfeng
AU - Nomoto, Keita
AU - Conibeer, Gavin
AU - Perez-Wurfl, Ivan
PY - 2016/6/21
Y1 - 2016/6/21
N2 - Silicon nanocrystals (Si NCs) embedded in a dielectric matrix is regarded as one of the most promising materials for the third generation photovoltaics, owing to their tunable bandgap that allows fabrication of optimized tandem devices. Previous work has demonstrated fabrication of Si NCs based tandem solar cells by sputter-annealing of thin multi-layers of silicon rich oxide and SiO2. However, these device efficiencies were much lower than expected given that their theoretical values are much higher. Thus, it is necessary to understand the practical conversion efficiency limits for these devices. In this article, practical efficiency limits of Si NC based double junction tandem cells determined by fundamental material properties such as minority carrier, mobility, and lifetime are investigated. The practical conversion efficiency limits for these devices are significantly different from the reported efficiency limits which use Shockley-Queisser assumptions. Results show that the practical efficiency limit of a double junction cell (1.6 eV Si NC top cell and a 25% efficient c-Si PERL cell as the bottom cell) is 32%. Based on these results suggestions for improvement to the performance of Si nanocrystal based tandem solar cells in terms of the different parameters that were simulated are presented.
AB - Silicon nanocrystals (Si NCs) embedded in a dielectric matrix is regarded as one of the most promising materials for the third generation photovoltaics, owing to their tunable bandgap that allows fabrication of optimized tandem devices. Previous work has demonstrated fabrication of Si NCs based tandem solar cells by sputter-annealing of thin multi-layers of silicon rich oxide and SiO2. However, these device efficiencies were much lower than expected given that their theoretical values are much higher. Thus, it is necessary to understand the practical conversion efficiency limits for these devices. In this article, practical efficiency limits of Si NC based double junction tandem cells determined by fundamental material properties such as minority carrier, mobility, and lifetime are investigated. The practical conversion efficiency limits for these devices are significantly different from the reported efficiency limits which use Shockley-Queisser assumptions. Results show that the practical efficiency limit of a double junction cell (1.6 eV Si NC top cell and a 25% efficient c-Si PERL cell as the bottom cell) is 32%. Based on these results suggestions for improvement to the performance of Si nanocrystal based tandem solar cells in terms of the different parameters that were simulated are presented.
UR - http://www.scopus.com/inward/record.url?scp=84975230564&partnerID=8YFLogxK
U2 - 10.1063/1.4954003
DO - 10.1063/1.4954003
M3 - Article
VL - 119
SP - 1
EP - 8
JO - Journal of Applied Physics
JF - Journal of Applied Physics
SN - 0021-8979
IS - 23
M1 - 233102
ER -