Appl. Phys. Lett. 110, 012103 (2017)

Recent experimental progress on the synthesis of 2D sheets of group-III nitrides is encouraging. Maria Stella Prete and colleagues from Italy and Germany have used density functional theory and Green's function many-body perturbation theory to customize and tune the electronic and optical properties of 2D group-III nitrides, suggesting that they are useful for realizing efficient light-harvesting devices. From their analysis of B-, Al-, Ga-, In- and Tl-based nitrides the authors showed it is possible to select an electronic gap from 0 eV to 6.7 eV (smaller group-III atomic number yields larger gap), which spans the ultraviolet to longer wavelengths. Cation composition tunes 2D heterostructures from type I to type II, which the authors proposed may be exploited in efficient light harvesting in III–V solar cells, with 2D InGaN and InTlN heterostructures as main candidates. Interestingly, by combining GaN and TlN with InN it may be possible to push the tuning out to the THz region, with InTlN sheets being a candidate for THz emitters and detectors.