EU PVSEC Programme Online
EU PVSEC 2021, 6 - 10 September 2021
Presentation: 2BO.4.4 Thermal Stability of Novel Hole-Selective Contacts for Silicon Wafer Solar Cells
Type: Oral
Date: Tuesday, 26th September 2017
17:00 - 18:30
Location / Room: RAI Congress Centre 1st Floor / Auditorium G102-103
Author(s): C.-Y. Lee, T. Zhang, K. Khoo, A. Abdallah, S. Rashkeev, N. Tabet, B. Hoex
Presenter / Speaker: C.-Y. Lee, UNSW Australia, Sydney, Australia
Event: Conference Conference
Session: 2BO.4 Novel Approaches for c-Si Solar Cells
Topic: 2. 3 Heterojunction Solar Cells
Keywords: Stability, Passivation, a-Si:H
Summary / Abstract: The thermal stability of novel hole selective contacts is of key importance when integrating these films into highefficiency silicon solar cells. In this work, we focus on the thermal stability of atomic layer deposited (ALD) WOx with and without an a-Si:H interface passivation layer. Hydrogen diffusion from a-Si:H to WOx layer was detected by both Fourier transform infrared spectroscopy and in-situ ultraviolet photoelectron spectroscopy for annealing temperatures above 180 oC. The work function decreased for higher annealing temperatures, but the decrease was slightly less for the samples with the a-Si:H interface passivation layer due to the H doping of WOx. An annealing temperature higher than 223 ºC results in insufficient workfunction for hole selectivity. In terms of surface passivation, it was found that the plasma-enhanced ALD of WOx introduced some plasma damage on the a-Si:H layer as was detected by injectiondependent effective lifetime measurement. Fortunately, this could be recovered by an annealing treatment at 220 ºC, resulting in an implied VOC of 730 mV. The results provide a promising potential of the implementation on ALD WOx for high-efficiency silicon solar cells.