Twisted monolayer black phosphorus nanoribbbons: Tunable electronic and optical properties

Using density functional theory with meta generalized gradient approximation functional, we investigate scalable electronic and optical properties in twisted hydrogen passivated monolayer black phosphorus nanoribbons (PNRs) by twisting around a specified axis while varying the twisting angle up to 5 degrees. We found that after twisting, the electronic tunability is significant for Armchair configuration of PNR (APNR). We have observed that the bandgap variation of H-passivated APNR upon twisting attains a maximum change of 132meV per degree twist, and the twisted APNR bandgap is close to the bandgap of oxygen passivated non-twisted ones. Similarly, optical properties of APNR vary significantly upon twisting, which was confirmed by analyzing absorption spectra and optical bandgap. The extended spectral region in twisted APNR, which broadens from the mid-infra-red to the visible region, approaches the oxygenated effect. This tunability of electronic bandgaps and optical properties would ameliorate PNR based optoelectronic devices.