Sub-Bandgap Luminescence from Doped Polycrystalline and Amorphous Silicon Films and Its Application to Understanding Passivating-Contact Solar Cells
Date
2018-10
Authors
Nguyen, Hieu
Liu, Anyao
Yan, Di
Guthrey, Harvey
Truong, Thien
Tebyetekerwa, Mike
Li, Ziyuan
Li, Zhuofeng
Al-Jassim, Mowafak M.
Cuevas, Andres
Journal Title
Journal ISSN
Volume Title
Publisher
American Chemical Society
Abstract
We report luminescence phenomena from doped polycrystalline silicon (poly-Si) films and their applications to study carrier transport properties in passivating-contact solar cells. Low-temperature luminescence spectra emitted from doped poly-Si layers are found to be very broad and stretched from the crystalline silicon (c-Si) luminescence peak to significantly lower energies. This suggests that these layers contain radiative defect levels whose energies are continuously distributed from the band edges to deep levels in the poly-Si bandgap. Moreover, photoinduced carriers inside poly-Si layers are found to be completely blocked by an ultrathin SiOx interlayer (∼1.3 nm). This demonstrates that there is no free-carrier coupling from poly-Si layers in practical passivating-contact solar cells. Finally, we demonstrate that the same principle can be applied to study carrier transport properties in hydrogenated amorphous silicon films.
Description
Keywords
amorphous silicon; luminescence; passivating contacts; polycrystalline silicon; solar cells; sub-bandgap
Citation
Collections
Source
ACS Applied Energy Materials
Type
Journal article
Book Title
Entity type
Access Statement
Open Access
License Rights
Restricted until
Downloads
File
Description
Author/s Accepted Manuscript (AAM) / Post-print