Nb₃Br₈ (Niobium Tribromide Cluster Compound)

Nb₃Br₈ (Niobium Tribromide Cluster Compound) — Introduction

Nb₃Br₈ is the bromine analog of Nb₃I₈, also featuring Nb₃ clusters. It shares similar structural motifs, but bromine substitution modifies the electronic structure, leading to a slightly larger band gap and different stability.

Physical Properties

Appearance: Dark crystalline solid.

Crystal Structure: Composed of triangular Nb₃ clusters surrounded by Br atoms, forming a layered arrangement.

Electronic Properties: A semiconductor with a band gap of ~0.6–0.8 eV, larger than Nb₃I₈ due to stronger electronegativity of Br.

Exfoliation: Quasi-layered but more strongly bonded than typical vdW halides → exfoliation is challenging, usually yielding few-layer flakes instead of true monolayers.

 Applications

Low-Dimensional Correlated Systems: Useful for exploring cluster-based electron correlation and magnetism.

Infrared to Visible Optoelectronics: Band gap closer to the visible spectrum than Nb₃I₈, making it suitable for photodetection across a broader range.

Quantum Transport: Promising material for studying pressure- or strain-induced electronic phase transitions.