Another 2D material – black phosphorus – is being researched because of its attractive band gap and charge carrier mobility. The researchers considered that GeSe was analogous to black phosphorus and could, therefore, be considered a pseudo group V element.
Under extreme pressure, black phosphorus is transformed into a simple cubic form and the Princeton researchers wondered if the same could be done to GeSe and heated alpha-GeSe to 1200°C under 6GPa of pressure.
“What we found was not only a new kind of GeSe, but that it also has this uncommon ‘boat’ conformation,” said researcher Fabian von Rohr. This compares with the ‘chair’ conformation of black phosphorus and alpha-GeSe.
The researchers have found that beta-GeSe has a band gap between that of black phosphorus and alpha-GeSe and say this could prove promising. Other benefits of GeSe include robustness under ambient conditions.
