Fast and safe synthesis of micron germanium in an ammonia atmosphere using MoN as catalyst.

Here, we reported a new method for fast and safe synthesis of a micron germanium (Ge) semiconductor. The Ge was successfully prepared from mixed GeO with a low amount of MoO by the NH reduction method at 800 °C for an ultra-short time of 10 min. XRD patterns show that the Ge has a tetragonal structure. SEM images show that the size of the Ge particles is from 5 μm to 10 μm, and so it is on the micron scale. UV-visible diffuse reflectance spectroscopy shows that the Ge has good light absorption both in the ultraviolet and visible regions. The formation of Ge mainly goes through a two-step conversion in the NH flow. Firstly, GeO is converted to GeN, and then GeN is decomposed to generate Ge. The comparison experiments of MoO and MoN demonstrate that MoN is the catalyst for the Ge synthesis which improves the GeN decomposition. The presented fast and safe synthesis method of Ge has great potential for industrialization and the proposed MoN boosting the GeN decomposition has provided significant guidance for other nitride decomposition systems.