Fast and safe synthesis of micron germanium in an ammonia atmosphere using Mo2N as catalyst

摘要

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 _(2) with a low amount of MoO _(3) by the NH _(3) 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 _(3) flow. Firstly, GeO _(2) is converted to Ge _(3) N _(4) , and then Ge _(3) N _(4) is decomposed to generate Ge. The comparison experiments of MoO _(3) and Mo _(2) N demonstrate that Mo _(2) N is the catalyst for the Ge synthesis which improves the Ge _(3) N _(4) decomposition. The presented fast and safe synthesis method of Ge has great potential for industrialization and the proposed Mo _(2) N boosting the Ge _(3) N _(4) decomposition has provided significant guidance for other nitride decomposition systems.