TY - GEN
T1 - High-density and well-ordered Si-nanodisk array with controllable band gap energy and high photon absorption coefficient for all-silicon tandem solar cell applications
AU - Huang, Chi Hsien
AU - Igarashi, Makoto
AU - Bin Budiman, Mohd Fairuz
AU - Wang, Xuan Yu
AU - Oshima, Ryuji
AU - Yamashita, Ichiro
AU - Okada, Yoshitaka
AU - Samukawa, Seiji
PY - 2010/12/20
Y1 - 2010/12/20
N2 - AII-Si tandem solar cells comprising quantum dot superlattice (ODSL) have attracted much attention. However, a fabrication to realize uniform and controllable OD size (determines band gap (Eg)) and spacing between ODs (generates miniband) in ODSL is still a big challenge. In this study, we created a two-dimensional sub-10nm-Sinano-disk array (2D Si-ND array) with a high-density and well-ordered arrangement using bio-template (Iron-oxide core) as a Φ-7-nm-etching-mask and an advanced etching process that included NF3 treatment and damage-free neutral beam (NB) etching. The 2D Si-ND array shows high photon absorption coefficient (>105 cm -1) and high PL intensity at room temperature owing to high-density 2D SiND (>7×1011 cm-2) and narrow spacing. The Eg and PL emission peaks can be easily controlled by changing the ND thickness. The Eg varied from 2.2 to 1.4 eV. To realize tandem solar cells, we also investigated fabricating stacked NDs, which is to stack the NDs along the 3rd dimension. The NDs were separated by 1-2nm-thick SiO2 that was formed by our developed NB oxidation (NBO) at 300°C. The tunneling current can be controlled by changing the tunneling junction thickness using NBO. Those results support the feasibility of our proposed processes for the high-efficiency all-Si tandem solar cells comprising ODSL.
AB - AII-Si tandem solar cells comprising quantum dot superlattice (ODSL) have attracted much attention. However, a fabrication to realize uniform and controllable OD size (determines band gap (Eg)) and spacing between ODs (generates miniband) in ODSL is still a big challenge. In this study, we created a two-dimensional sub-10nm-Sinano-disk array (2D Si-ND array) with a high-density and well-ordered arrangement using bio-template (Iron-oxide core) as a Φ-7-nm-etching-mask and an advanced etching process that included NF3 treatment and damage-free neutral beam (NB) etching. The 2D Si-ND array shows high photon absorption coefficient (>105 cm -1) and high PL intensity at room temperature owing to high-density 2D SiND (>7×1011 cm-2) and narrow spacing. The Eg and PL emission peaks can be easily controlled by changing the ND thickness. The Eg varied from 2.2 to 1.4 eV. To realize tandem solar cells, we also investigated fabricating stacked NDs, which is to stack the NDs along the 3rd dimension. The NDs were separated by 1-2nm-thick SiO2 that was formed by our developed NB oxidation (NBO) at 300°C. The tunneling current can be controlled by changing the tunneling junction thickness using NBO. Those results support the feasibility of our proposed processes for the high-efficiency all-Si tandem solar cells comprising ODSL.
UR - http://www.scopus.com/inward/record.url?scp=78650129373&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=78650129373&partnerID=8YFLogxK
U2 - 10.1109/PVSC.2010.5614043
DO - 10.1109/PVSC.2010.5614043
M3 - Conference contribution
AN - SCOPUS:78650129373
SN - 9781424458912
T3 - Conference Record of the IEEE Photovoltaic Specialists Conference
SP - 1223
EP - 1227
BT - Program - 35th IEEE Photovoltaic Specialists Conference, PVSC 2010
T2 - 35th IEEE Photovoltaic Specialists Conference, PVSC 2010
Y2 - 20 June 2010 through 25 June 2010
ER -