# Violet Arsenic Phosphorus: Switching p-Type into High Performance n-Type Semiconductor by Arsenic Substitution

## TL;DR

Researchers created a new semiconductor material by substituting arsenic into violet phosphorus, switching it from p-type to high-performance n-type with excellent electron mobility.

## Contribution

The first synthesis of violet arsenic phosphorus and its demonstration as a high-performance n-type semiconductor through arsenic substitution.

## Key findings

- Arsenic substitution in violet phosphorus reduces effective electron mass and increases electron mobility to 2622.503 cm² V⁻¹ s⁻¹.
- Field effect transistors made from violet arsenic phosphorus show electron mobility of 137.06 cm² V⁻¹ s⁻¹, much higher than hole mobility in violet phosphorus.
- The material retains high performance under ambient conditions for 5 hours.

## Abstract

Violet arsenic phosphorus (VP-As) single crystals were synthesized and characterized by single crystal X-ray diffraction to be P83.4As0.6 (CSD-2408761), the P12 is occupied by arsenic/phosphorus as a mixed occupancy site.The p-type VP has been switched into n-type VP-As, the effective electron mass was significantly reduced and resulted in high electron mobility of 2622.503 cm2 V−1 s−1.High electron mobility of 137.06 cm2 V−1 s−1 has been achieved from field effect transistor, much higher than the hole mobility of VP.

Violet arsenic phosphorus (VP-As) single crystals were synthesized and characterized by single crystal X-ray diffraction to be P83.4As0.6 (CSD-2408761), the P12 is occupied by arsenic/phosphorus as a mixed occupancy site.

The p-type VP has been switched into n-type VP-As, the effective electron mass was significantly reduced and resulted in high electron mobility of 2622.503 cm2 V−1 s−1.

High electron mobility of 137.06 cm2 V−1 s−1 has been achieved from field effect transistor, much higher than the hole mobility of VP.

The online version contains supplementary material available at 10.1007/s40820-025-01956-1.

Violet phosphorus, a recently explored layered elemental semiconductor, has attracted much attention due to its unique photoelectric, mechanical properties, and high hole mobility. Herein, violet arsenic phosphorus has for the first time been synthesized by a molten lead method. The crystal structure of violet arsenic phosphorus (P83.4As0.6, CSD-2408761) was determined by single crystal X-ray diffraction to have similar structure as that of violet phosphorus, where P12 is occupied by arsenic/phosphorus (As/P) atoms as mixed occupancy sites As1/P12. The arsenic substitution has been demonstrated to tune the band structure of violet phosphorus, switching p-type of violet phosphorus to high-performance n-type violet arsenic phosphorus. The effective electron mass along the < 010 > direction is significantly reduced from 1.792 to 0.515 m0 by arsenic substitution, resulting in an extremely high electron mobility of 2622.503 cm2 V⁻1 s⁻1. The field effect transistor built with P83.4As0.6 nanosheets was measured to have a high electron mobility (137.06 cm2 V⁻1 s⁻1, 61.2 nm), even under ambient conditions for 5 h, much higher than the hole mobility of violet phosphorene nanosheets (4.07 cm2 V⁻1 s⁻1, 73.3 nm). This work provides a new idea for designing phosphorus-based materials for field effect transistors, giving significant potential in complementary metal–oxide–semiconductor applications.

The online version contains supplementary material available at 10.1007/s40820-025-01956-1.