Direct Gas Phase Synthesis of High Purity Black Arsenic Phosphorus with Non-Metallic Mineralizer

Abstract

2D black arsenic phosphorus (b-AsP) is a promising candidate for infrared photodetectors. However, it is an intractable task to directly synthesize high-purity b-AsP crystals under the existing system. Herein, we report a novel system for synthesis of high purity b-AsP crystals with non-metallic mineralizer, in which a small amount of I2 was chosen as the sole additive for the synthesis of b-AsP to avoid metal by-products, and the removal of impurities were realized through the reverse heating program after reaction. Through optimization of process conditions, the ultra-high conversion rate of b-AsP was >99%, and the purity of b-AsP crystal was as high as >99.9% with favorable crystal form, with diameter of ~5 mm and typical polycrystalline characteristics, and the entire synthesis process took only 15 h. This facile and green route for b-AsP crystals synthesis might be expected to replace the existing b-AsP synthesis system and provide theoretical guidance for the breakthrough of the synthesis reaction mechanism of b-AsP materials.

Keywords: Black arsenic phosphorus, Non-metallic mineralizer, High purity, Ultra-high conversion, Facile synthesis