skip to main content
US FlagAn official website of the United States government
dot gov icon
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
https lock icon
Secure .gov websites use HTTPS
A lock ( lock ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.


Search for: All records

Creators/Authors contains: "Ekuma, Chinedu E."

Note: When clicking on a Digital Object Identifier (DOI) number, you will be taken to an external site maintained by the publisher. Some full text articles may not yet be available without a charge during the embargo (administrative interval).
What is a DOI Number?

Some links on this page may take you to non-federal websites. Their policies may differ from this site.

  1. Free, publicly-accessible full text available May 1, 2026
  2. A new generation of quantum material derived from intercalating zerovalent atoms such as Cu into the intrinsic van der Waals gap at the interface of atomically thin two-dimensional GeSe/SnS heterostructure is designed, and their optoelectronic features are explored for next-generation photovoltaic applications. Advanced ab initio modeling reveals that many-body effects induce intermediate band (IB) states, with subband gaps (~0.78 and 1.26 electron volts) ideal for next-generation solar devices, which promise efficiency greater than the Shockley-Queisser limit of ~32%. The charge carriers across the heterojunction are both energetically and spontaneously spatially confined, reducing nonradiative recombination and boosting quantum efficiency. Using this IB material in a solar cell prototype enhances absorption and carrier generation in the near-infrared to visible light range. Tuning the active layer’s thickness increases optical activity at wavelengths greater than 600 nm, achieving ~190% external quantum efficiency over a broad solar wavelength range, underscoring its potential in advanced photovoltaic technology. 
    more » « less
  3. We report the mechanical properties of cubic boron nitride (c-BN) and diamond under the combined impact of dynamical pressure and temperature, calculated using ab initio molecular dynamics. Our study revealed a pronounced sensitivity of the mechanical properties of c-BN to applied pressure. Notably, c-BN undergoes a brittle-to-ductile transition at ∼220 GPa, consistent across various dynamical temperatures, while diamond exhibits no such transition. Furthermore, the Vickers hardness profile for c-BN closely mirrors that of diamond across a spectrum of temperature–pressure conditions, highlighting c-BN's significant mechanical robustness. These results underscore the superior resilience and adaptability of c-BN compared to diamond, suggesting its potential as an ideal candidate for applications in extreme environments. 
    more » « less