Si3AlP: A new promising material for solar cell absorber

TL;DR

This study uses first-principles calculations to explore Si3AlP, a promising new alloy with improved optical properties for solar cells, potentially enhancing silicon-based photovoltaic efficiency.

Contribution

The paper introduces Si3AlP as a stable, optoelectronically advantageous alloy with unique band gap properties suitable for solar cell applications.

Findings

Si3AlP has a larger fundamental band gap than silicon.

It exhibits higher absorption in the visible light spectrum.

The study provides insights into stability and band structure engineering for semiconductor alloys.

Abstract

First-principles calculations are performed to study the structural and optoelectronic properties of the newly synthesized nonisovalent and lattice-matched (Si2)0.6(AlP)0.4 alloy [T. Watkins et al., J. Am. Chem. Soc. 2011, 133, 16212.] We find that the ordered CC-Si3AlP with a basic unit of one P atom surrounded by three Si atoms and one Al atom is the most stable one within the experimentally observed unit cell.1 Si3AlP has a larger fundamental band gap and a smaller direct band gap than Si, thus it has much higher absorption in the visible light region. The calculated properties of Si3AlP suggest that it is a promising candidate for improving the performance of the existing Si-based solar cells. The understanding on the stability and band structure engineering obtained in this study is general and can be applied for future study of other nonisovalent and lattice-matched semiconductor alloys.