Structure‐Induced Stability in Sinuous Black Silicon for Enhanced Hydrogen Evolution Reaction Performance. (18th February 2021)

• Record Type: Journal Article
• Authors: Patrick, Margaret; Yang, Fan; Vakki, Waltteri; Aguiar, Jeffery A.; Gu, Jing
• Is Part Of: Advanced functional materials. Volume 31:Number 16(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-02-18
• Subjects: black silicon -- hydrogen evolution reaction -- photoelectrochemical conversion -- solar energy conversion -- structure‐induced stability; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adfm.202008888
• Languages: English
• ISSNs: 1616-301X

Abstract

Abstract: Clean energy infrastructures of the future depend on efficient, low‐cost, long‐lasting systems for the conversion and storage of solar energy. This is currently limited by the durability and economic viability of today's solar energy systems. These limitations arise from a variety of technical challenges; primarily, a need remains for the development of stable solar absorber–catalyst interfaces and improved understanding of their mechanisms. Although thin film oxides formed via atomic layer deposition have been widely employed between the solar absorber–catalyst interfaces to improve the stability of photoelectrochemical devices, few stabilization strategies have focused on improving the intrinsic durability of the semiconductor. Here, a sinuous black silicon photocathode (s‐bSi) with intrinsically improved stability owing to the twisted nanostructure is demonstrated. Unlike columnar black silicon with rapidly decaying photocurrent density, s‐bSi shows profound stability in strong acid, neutral, and harsh alkaline conditions during a 24‐h electrolysis. Furthermore, scanning transmission electron microscopy studies prior to and post electrolysis demonstrate limited silicon oxide growth inside the walls of s‐bSi. To the authors' knowledge, this is the first time structure‐induced stability has been reported for enhancing the stability of a photoelectrode/catalyst interface for solar energy conversion. Abstract : A unique sinuous nanoporous black silicon interface is shown to outperform the common columnar analog in terms of stability and hydrogen evolution reaction performance in pH 1‐14 conditions. The improvement is attributed to structure‐induced interface protection, where the twisted morphology inhibits oxide growth and subsequent degradation. These findings can be applied to the design of other photoabsorber and electronic systems.