Lattice Expansion in Optimally Doped Manganese Oxide: An Effective Structural Parameter for Enhanced Thermochemical Water Splitting

Date

2019

Authors

Gao, Xiang (Michael)
Di Bernardo, Iolanda
Kreider, Peter
Tran, Phu Thanh
Cai, Xiangbin
Wang, Ning
Zhu, Ye
Brahmadesham Venkataraman, Mahesh
Lipton-Duffin, Josh
Bayon, Alicia

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Volume Title

Publisher

American Chemical Society

Abstract

Herein, posttreatment techniques of phosphorus-doped poly-Si/SiOx passivating contacts, including forming gas annealing (FGA), atomic layer deposition (ALD) of hydrogenated aluminum oxide (AlOx:H), and plasma-enhanced chemical vapor deposition (PECVD) of hydrogenated silicon nitride (SiNx:H), are investigated and compared in terms of their application to silicon solar cells. A simple FGA posttreatment produces a significant increase in the implied open circuit voltage (iVoc) and the effective minority-carrier lifetime (τeff) of high-resistivity crystalline Si (c-Si) samples, whereas low-resistivity samples show a minimal change. Treatment by means of AlOx:H and/or SiNx:H followed by postdeposition FGA results in a universal increase in τeff and iVoc for all substrate resistivities (as high as 12.5 ms and 728 mV for 100 Ω cm and 5.4 ms and 727 mV for 2 Ω cm n-type c-Si substrates). In addition, both the FGA and AlOx:H + FGA techniques can inject sufficient hydrogen into the samples to passivate defects at the SiOx/c-Si and poly-Si/SiOx interfaces. However, this hydrogen concentration is insufficient to neutralize both the nonradiative defects inside the poly-Si films and dangling bonds associated with the amorphous Si phase present in them. The hydrogen injected by the SiNx:H + FGA technique can passivate both the interfaces and the defects and dangling bonds within the poly-Si film. These results are confirmed by low-temperature photoluminescence spectroscopy, Fourier transform infrared spectroscopy, and dynamic secondary-ion mass spectrometry measurements.

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Source

ACS Catalysis

Type

Journal article

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Restricted until

2099-12-31