Computational design of compounds for monolithic integration in optoelectronics - art. no. 035306

A class of semiconductors is introduced and their physical properties are e xamined using both ab initio total-energy calculations and quasiparticle GW calculations. These compounds are designed to address problems of lattice- constant mismatch and polarity mismatch that are common issues in heteroepi taxial growth of III-V alloys on silicon substrates. A variety of configura tions of these materials is explored. It is found that their lattice consta nts and band gaps fall into a region of phase space different from that of conventional semiconductors, making them potential candidates for the basis of optical devices-infrared emitters and detectors. A particular suitable configuration is identified that is lattice-constant matched to Si and has a direct band gap of 0.8 eV. This gap corresponds to the canonical waveleng th of 1.5 mum in optoelectronics. Thus this material could ultimately enabl e tractable monolithic integration of optics with electronics. The characte ristics of this particular configuration are examined in depth, including i ts temperature dependence, its bulk energetics, and its growth energetics. The results of these analyses indicate that fabrication of these compounds using heteroepitaxial growth techniques should be feasible.