Strong Coupling with Light Enhances the Photoisomerization Quantum Yield of Azobenzene

The strong coupling between molecules and photons in resonant cavities offers a new toolbox to manipulate photochemical reactions. Although the quenching of photochemical reactions in the strong coupling regimen has been demonstrated before, their enhancement has proven to be more elusive. Here, by means of a state-of-the-art approach, we show how the trans- cis photoisomerization quantum yield of azobenzene embedded in a realistic environment can be higher in polaritonic conditions than in the cavity-free case. We characterize the mechanism leading to such enhancement and discuss the conditions to push the photostationary state toward the unfavored reaction product. Our results provide a signature that the control of photochemical reactions through strong coupling can be extended from selective quenching to improvement of the quantum yields.