A Novel Laser‐Stimulated Technique for Direct Formation of Few‐Layer Phosphorene on Silicon Substrates

Abstract

Direct formation of few‐layered phosphorene flakes through a laser stimulated crystallization on silicon substrates is reported. The formation of such layers is initiated by depositing red phosphorus (RP) on silicon followed by laser‐induced crystallization. After deposition, a glass plate is used to encapsulate the amorphous layer on the substrate. Being capable of a programmable scanning, a 1064‐nm laser is used as the source to impart energy onto the RP layer and to achieve the desired allotrope transformation. Exposure to laser beam at the presence of temperature and local pressure exerted by argon ambient leads to the conversion of amorphous material into crystalline flakes. Furthermore, interesting core‐shell, flower‐like and vertical structures are achieved. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), atomic force microscopy (AFM), Raman spectroscopy and energy dispersive X‐ray spectroscopy (EDS) are used to examine the conversion of red phosphorus into few‐layer phosphorene flakes. These flakes are used to fabricate a photodetector with a reasonable response to green laser and a field‐effect transistor with a mobility of 12 cm2 V−1 s−1, further indicating the evolution of well‐crystalline layers. The fabricated transistors demonstrate triode and saturation regimes in their electrical response, evidencing their high quality.