Fig. 1. Structure and thermal stability of monolayer C₂B₆. Atomic structure at -2 V voltage （a） and the simulated STM configuration （b）； energy and temperature of monolayer C₂B₆ in AIMD calculation with 10 ps at 300 K （c） and 600 K （d）， the blue and black spheres represent B and C atoms， respectively

Fig. 2. Phonon spectrum of monolayer C₂B₆ and vibration modes obtained from perturbation density functional calculations. （a） Phonon spectrum； （b） atomic vibration modes of the first 9 orders

Fig. 3. Band structure and density of states of the monolayer C₂B₆. Band structure calculated by PBE （a）， projected band structure calculated by HSE06 （b）， and density of states （c）

Fig. 4. Energy and band edge position of monolayer C₂B₆ under external strain： the difference in energy （a） and band edge position （b） in the x and y directions

Fig. 5. Monolayer C₂B₆ photodetector model （a） and photocurrent calculated along the x （b） and y （c） directions