Two-Dimensional Phosphorus Allotropes and Their Applications

Two-dimensional phosphorus allotropes encompass a family of atomically thin materials derived from distinct bulk phases of the element. The most widely studied member is phosphorene, the monolayer form of black phosphorus, which combines a moderate direct bandgap with high carrier mobility and strong in-plane anisotropy. In parallel, violet phosphorus and Hittorf’s phosphorus have emerged as stable van der Waals semiconductors with tunable optical transitions and potential for high-frequency and photonic devices. Recent advances include bottom-up and top-down synthesis routes for fibrous red phosphorus, yielding one-dimensional substructures integrated into 2D architectures with giant linear and nonlinear optical anisotropy. Data-driven and machine-learning methods have further expanded the structural landscape to novel lattice topologies and cage-based frameworks, while bandgap engineering via strain, layer control or chemical doping offers routes to bespoke optoelectronic properties. Practical applications span photodetectors, flexible electronics, spintronic devices and energy-storage electrodes, although ambient instability and surface reactivity remain critical challenges. Progress in passivation strategies and inert-gas processing has begun to address degradation pathways, paving the way for robust device integration. Collectively, these developments position two-dimensional phosphorus allotropes as versatile platforms for next-generation electronics, photonics and sensing technologies.

Research from Nature Portfolio

Recent studies have demonstrated a bottom-up chemical-vapour-transport approach to synthesise quasi-one-dimensional fibrous red phosphorus flakes with preferred orientation, enabling exploration of their intrinsic optical anisotropy and integration as micro phase retarders in polarisation-conversion devices. Investigations have also uncovered exceptionally large linear and third-order nonlinear optical anisotropy in fibrous red phosphorus, with photoluminescence and harmonic-generation efficiencies surpassing those of benchmark two-dimensional materials. These findings establish fibrous red phosphorus as a promising candidate for advanced photonic and optoelectronic applications.

Two-Dimensional Phosphorus Allotropes and Their Applications publication trend

The graph below shows the total number of articles in two-dimensional phosphorus allotropes and their applications across all publications each year (not limited to Nature Index journals).

Technical terms

Allotrope: A distinct structural form of the same chemical element.

Phosphorene: Monolayer or few-layer black phosphorus with a direct bandgap and high mobility.

Van der Waals material: A layered crystal held together by weak interlayer forces permitting facile exfoliation.

Bandgap: The energy difference between valence and conduction bands in a semiconductor.

Anisotropy: Direction-dependent variation of physical properties.

Exciton: A bound electron–hole pair within a semiconductor.

Passivation: Surface treatment that prevents chemical degradation or excessive reactivity.

References

1. Polarization conversion in bottom-up grown quasi-1D fibrous red phosphorus flakes. Nature Communications (2023).
2. Giant anisotropic photonics in the 1D van der Waals semiconductor fibrous red phosphorus. Nature Communications (2021).
3. Hierarchically Structured Allotropes of Phosphorus from Data‐Driven Exploration. Angewandte Chemie International Edition (2020).
4. Single-Layered Hittorf’s Phosphorus: A Wide-Bandgap High Mobility 2D Material. Nano Letters (2016).
5. Bound excitons and bandgap engineering in violet phosphorus. npj 2D Materials and Applications (2023).
6. Photodegradation and van der Waals Passivation of Violet Phosphorus. Nanomaterials (2024).