Facile Synthesis of Two-Dimensional (2D) Materials to Discover New Compounds and Stabilize Metastable Modifications

Two-dimensional materials remain one of the hottest research fields for a few decades due to their emerging physical properties existing in a single atomic layer or a few atomic layers. After intensive research efforts, 2D materials started to find their applications in our daily life, such as in batteries, electronics, or even bulletproof vests. To turn on the functionalities of 2D materials, controlled synthesis of 2D materials is the first and most crucial step. In general, high-temperature solid-state reactions, solution-phase growth, vapor deposition, molecular-beam epitaxy (MBE) method, etc. were widely adopted to grow 2D materials. All these methods proved to be very successful to prepare 2D materials. But worth mentioning, many challenges such as requiring high energy, expensive instruments involved, easily producing thermodynamically stable phases, etc. remain and impede the broader applications of 2D materials. In this work, we will present facile synthesis methods for discovering a new phosphorus allotrope, violet-P₁₁, via a low-temperature flux method and stabilization and growth of the metastable 6R-TaS₂ phase. Violet-P₁₁ is a large bandgap 2D semiconductor of E_g=~ 2 eV with good ambient stability. 6R-TaS₂ is a metastable phase, which is not easily accessed by conventional synthetic methods.