Electronic properties of two-dimensional phosphorus allotropes using DFT-1/2

Accurately predicting the electronic properties of two-dimensional phosphorus allotropes is essential for their use in nanoelectronics. However, traditional methods, such as density functional theory (DFT) with the generalized gradient approximation (GGA), tend to systematically underestimate their band gap (Eg), which limits their predictive capabilities. In this study, we address this limitation by applying the DFT-1/2 method to correct the Perdew–Burke–Ernzerhof (PBE) exchange–correlation functional. We perform a systematic study on four key allotropes — Black, Blue, Green, and Red Phosphorene — using the SIESTA implementation of DFT. The DFT-1/2 method consistently widens the band gap, yielding values intermediate between those obtained with GGA-PBE and those from more computationally demanding methods like hybrid functionals (HSE) or many-particle corrections. Our findings validate the DFT-1/2 method as a computationally efficient yet more accurate tool for characterizing the electronic properties of 2D semiconductors, and we report the specific parameters that ensure the reproducibility of our results.