First evidence of stable P–N bonds after anodic treatment of InP in liquid ammonia: A new III–V material passivation route

This work reports – for the first time – the electrochemical anodic passivation of InP in a relevant nonaqueous solvent: liquid ammonia. A new route of InP passivation was clearly established by the coupling approach electrochemistry-XPS analyses. A specific P–N surface bond chemistry was evidenced and associated to a phosphinimidic amide-like electrodeposition. The efficiency of this new passivation route was supported by the high stability of the complete covering thin film since no air ageing effect is detected on InP surface for both types. The phosphazene surface termination offers new possibilities for further high-speed optoelectronic applications and functional molecular grafting.