Graded Layer Modification for High Efficiency Hydrogenated Amorphous Silicon--Germanium Solar Cells

Hydrogenated amorphous silicon--germanium (a-SiGe:H) solar cells are fabricated with different thicknesses of the i/n graded layer and profiling shapes for appropriate band gap profiling. Comparison of the solar parameters between the U-shape profiling and the exponential shape (E-shape) profiling h...

Full description

Saved in:
Bibliographic Details
Published in:Japanese Journal of Applied Physics 2012-10, Vol.51 (10), p.10NB16-10NB16-4
Main Authors: Chung, Jin-Won, Park, Jun Woong, Lee, Yu Jin, Ahn, Seh-Won, Lee, Heon-Min, Park, O Ok
Format: Article
Language:English
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Hydrogenated amorphous silicon--germanium (a-SiGe:H) solar cells are fabricated with different thicknesses of the i/n graded layer and profiling shapes for appropriate band gap profiling. Comparison of the solar parameters between the U-shape profiling and the exponential shape (E-shape) profiling has been carried out at the same total thickness. In the U-shape profiling, as the thickness of the i/n graded layer increase, the fill factor (FF) and open circuit voltage ($V_{\text{oc}}$) of p--i--n single-junction a-SiGe:H solar cells increase, but the short circuit current ($J_{\text{sc}}$) of cells decreases. In the E-shape profiling, the $J_{\text{sc}}$ of the a-SiGe:H cell is enhanced without significant losses in $V_{\text{oc}}$. For further analysis, a modified E-shape profiling is incorporated in a-Si:H/a-SiGe:H double-junction cells, which has resulted in the improvement of $V_{\text{oc}}$ and FF of double-junction cells to 1.67 V and 0.753, respectively, without significant reduction in $J_{\text{sc,SiGe}}^{\text{QE}}$, 12.58 mA/cm 2 .
ISSN:0021-4922
1347-4065
DOI:10.1143/JJAP.51.10NB16