Title |
High Performance Amorphous Silicon Oxide Thin Film Solar Cells Fabricated at Very Low Temperature |
DOI |
https://doi.org/10.5370/KIEE.2016.65.10.1694 |
Keywords |
Amorphous silicon oxide ; Photosensitivity ; Conductivity ; Thin film solar cell |
Abstract |
Present thin film solar cells with hydrogenated amorphous silicon oxide (a-SiO:H) as an absorber suffer from low fill factor(FF) of 61~64 [%] in spite of its benefits related to high open circuit voltage (V_{oc}). Since degraded quality of a-SiO:H absorber by alloying with oxygen can affect the FF, we aimed to achieve high photosensitivity by minimizing CO_2 gas addition. Improving optical gap(E_{opt}) has been attained by strong hydrogen dilution combined with lowering substrate temperature down to 100 [°C]. Small amount of the CO_2 was added in order to disturb microcrystalline formation by high hydrogen dilution. The developed a-SiO:H has high photosensitivity (~2×10^5) and high E_{opt} of 1.85 [eV], which contributed to attain remarkable FF of 74 [%] and high V_{oc} (>1 [V]). As a result, high power conversion efficiency of 7.18 [%] was demonstrated by using very thin absorber layer of only 100 [nm], even though we processed all experiment at extremely low temperature of 100 [°C]. |