Quantum Confinement and Anisotropic Electron–Phonon Coupling in Monolayer Phosphorene via Resonant Raman Spectroscopy

We present a first‐principles investigation of the resonant Raman spectra of black phosphorene (BP)—hereafter referred to as BP—using density functional theory (DFT) as implemented in the QERaman package. Our calculations reveal a direct bandgap of in BP, consistent with previous studies. The joint density of states (JDOS) and optical absorption spectra exhibit a broad feature spanning 3–, suggesting strong resonant Raman enhancement in this energy range. Polarized Raman spectroscopy in both parallel (VV) and cross (VH) configurations identifies the characteristic vibrational modes of BP, which we assign to the B, A, A, and B phonon modes of the point group. These findings provide critical insights into the electron–phonon coupling and optical response of BP, reinforcing its potential for optoelectronic applications.