Site-Selective Passivation of Defects in NiO Solar Photocathodes by Targeted Atomic Deposition

详细信息    查看全文

• 作者：Cory J. Flynn ; Shannon M. McCullough ; EunBi Oh ; Lesheng Li ; Candy C. Mercado ; Byron H. Farnum ; Wentao Li ; Carrie L. Donley ; Wei You ; Arthur J. Nozik ; James R. McBride ; Thomas J. Meyer ; Yosuke Kanai ; James F. Cahoon
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2016
• 出版时间：February 24, 2016
• 年：2016
• 卷：8
• 期：7
• 页码：4754-4761
• 全文大小：469K
• ISSN：1944-8252

文摘

For nanomaterials, surface chemistry can dictate fundamental material properties, including charge-carrier lifetimes, doping levels, and electrical mobilities. In devices, surface defects are usually the key limiting factor for performance, particularly in solar-energy applications. Here, we develop a strategy to uniformly and selectively passivate defect sites in semiconductor nanomaterials using a vapor-phase process termed targeted atomic deposition (TAD). Because defects often consist of atomic vacancies and dangling bonds with heightened reactivity, we observe—for the widely used p-type cathode nickel oxide—that a volatile precursor such as trimethylaluminum can undergo a kinetically limited selective reaction with these sites. The TAD process eliminates all measurable defects in NiO, leading to a nearly 3-fold improvement in the performance of dye-sensitized solar cells. Our results suggest that TAD could be implemented with a range of vapor-phase precursors and be developed into a general strategy to passivate defects in zero-, one-, and two-dimensional nanomaterials.