Electronic properties of pseudocubic IV-V compounds with 3:4 stoichiometry: Chemical trends

►The chemical trends for structural and electronic properties of IV3V4 compounds (C3N4, Si3N4, Ge3N4, Sn3N4, C3P4, Si3P4, Ge3P4, Sn3P4, C3As4, Si3As4, Ge3As4, and Sn3As4) in pseudocubic structures have been obtained by DFT + GW calculations. ►Trends for relationship among cohesive energy, bulk modulus and nearest-neighbor distance of IV3V4 compounds are obtained. A modified empirical formula was proposed to accurately calculate the bulk modulus of IV3V4 compounds in pseudocubic structure. ►The relationship between the band gap and molecular weight of IV3V4 compounds is quite different from that of semiconductors and insulators in groups II-VI, III-V, and IV. Specifically, for IV-phosphides and IV-arsenides, there is an anomalous 'v' shape in the band gap as a function of molecular weight. ►IV3V4 compounds in pseudocubic structure are semiconductors, with the exception of C3P4 and C3As4. An empirical formula was proposed to predict band gaps in terms of the electronegativities of elements and bond lengths of compounds. ►A proposal of IV3V4 compounds for solar energy application is made and the possibility of band gap tunability by strain engineering is suggested.