Abstract
We investigate how SiOx oxide interlayers prepared by different techniques (chemical, thermal) in combination with hydrogen released from an ALD Al2O3 source layer govern passivation in 1) passivated contacts based on doped poly-Si layers and tunneling SiO2, and 2) wafer surface passivation by Al2O3. Profiles of O and H in these structures with engineered, buried SiOx interlayers were measured by Time-of-Flight SIMS (TOF-SIMS) at nanometer resolution. Passivated contacts perform best with thermally oxidized SiOx, while chemical SiOx causes poly-Si film blistering and performance degradation. ALD Al2O3 acts as passivating H source, significantly improving B-doped and intrinsic poly-Si contacts for IBC cells. Fast-diffusing hydrogen from the Al2O3 source layer appears to penetrate Si wafer thickness, improving the passivation of structures at the opposite side. In contrast to the passivated contacts, chemical SiOx interlayer promotes wafer surface passivation by ALD Al2O3, while similarly thin thermal SiO2 suppresses passivation and built-in charge.
Original language | American English |
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Pages (from-to) | 295-301 |
Number of pages | 7 |
Journal | Energy Procedia |
Volume | 124 |
DOIs | |
State | Published - 2017 |
Event | 7th International Conference on Silicon Photovoltaics, SiliconPV 2017 - Freiburg, Germany Duration: 3 Apr 2017 → 5 Apr 2017 |
Bibliographical note
Publisher Copyright:© 2017 The Authors. Published by Elsevier Ltd.
NREL Publication Number
- NREL/JA-5J00-68706
Keywords
- AlO
- passivated contact
- passivation
- polysilicon
- silicon