Light-induced V{sub oc} increase and decrease in high-efficiency amorphous silicon solar cells
Journal Article
·
· Journal of Applied Physics
- Ecole Polytechnique Fédérale de Lausanne (EPFL), Institute of Microengineering (IMT), Photovoltaics and Thin-Film Electronics Laboratory, Rue de la Maladière 71, CH-2000 Neuchâtel (Switzerland)
High-efficiency amorphous silicon (a-Si:H) solar cells were deposited with different thicknesses of the p-type amorphous silicon carbide layer on substrates of varying roughness. We observed a light-induced open-circuit voltage (V{sub oc}) increase upon light soaking for thin p-layers, but a decrease for thick p-layers. Further, the V{sub oc} increase is enhanced with increasing substrate roughness. After correction of the p-layer thickness for the increased surface area of rough substrates, we can exclude varying the effective p-layer thickness as the cause of the substrate roughness dependence. Instead, we explain the observations by an increase of the dangling-bond density in both the p-layer—causing a V{sub oc} increase—and in the intrinsic absorber layer, causing a V{sub oc} decrease. We present a mechanism for the light-induced increase and decrease, justified by the investigation of light-induced changes of the p-layer and supported by Advanced Semiconductor Analysis simulation. We conclude that a shift of the electron quasi-Fermi level towards the conduction band is the reason for the observed V{sub oc} enhancements, and poor amorphous silicon quality on rough substrates enhances this effect.
- OSTI ID:
- 22314407
- Journal Information:
- Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 9 Vol. 116; ISSN JAPIAU; ISSN 0021-8979
- Country of Publication:
- United States
- Language:
- English
Similar Records
H{sub 2}-dilution vs. buffer layers for increased V{sub oc}
Materials Optimization for Silicon Heterojunction Solar Cells Using Spectroscopic Ellipsometry
In-situ hydrogen microstructural characterization of Si heterojunction passivation: Addressing VOC degradation and mitigation pathways
Book
·
Mon Dec 30 23:00:00 EST 1996
·
OSTI ID:527615
Materials Optimization for Silicon Heterojunction Solar Cells Using Spectroscopic Ellipsometry
Conference
·
Sun Dec 31 23:00:00 EST 2006
·
OSTI ID:978495
In-situ hydrogen microstructural characterization of Si heterojunction passivation: Addressing VOC degradation and mitigation pathways
Technical Report
·
Mon Jul 29 00:00:00 EDT 2024
·
OSTI ID:2478089