Abstract
The charge carrier transport mechanism of passivating contacts which feature an ultra-thin oxide layer is investigated by studying temperature-dependent current-voltage characteristics. 4-Terminal dark J-V measurements at low temperatures reveal non-linear J-V characteristics of passivating contacts with a homogeneously grown silicon oxide, which result in an exponential increase in contact resistance towards lower temperature. The attempt to describe the R(T) characteristic solely by thermionic emission of charge carriers across an energy barrier leads to a significant underestimation of the resistance by several orders of magnitude. However, the data can be described properly with the metal-insulator-semiconductor (MIS) theory if tunneling of charge carriers through the silicon oxide layer is taken into account. Furthermore, temperature-dependent light J-V characteristics of solar cells featuring passivating contacts at the rear revealed a FF drop at T < 205 K, which is near the onset temperature of the exponential increase in contact resistivity.
Original language | American English |
---|---|
Pages (from-to) | 15-19 |
Number of pages | 5 |
Journal | Solar Energy Materials and Solar Cells |
Volume | 178 |
DOIs | |
State | Published - 2018 |
Bibliographical note
Publisher Copyright:© 2018 Elsevier B.V.
NREL Publication Number
- NREL/JA-5900-72056
Keywords
- Passivating contacts
- Poly-Si
- Quantum mechanical tunneling
- Solar cells
- TOPCon