59
respectively. In the set A, metals which may lead to magnetic compounds
have been ignored due to large degree of uncertainty in their bandgap calculations
whereas set B contains non-metals. First principle calculations were
carried out to determine the stability and bandgap of all the compounds. We
systematically arrange the compounds in tabular form using Pettifor maps
which involves the ordering of elements based on the their chemical scale factor
118. We also explore alloys of 32 binary compounds having the band gap
in the range of 1.0-3.5 eV inspired by recent experiments on solid solutions for
photo-electrochemical water splitting applications 119, 3. Clustering analysis
120 of the alloy compounds divides 32 compounds into different groups with
compound belonging to the same group behaving similarly for bandgaps upon
alloying, thus giving the freedom too choose one compound over the other from
the same class if required.
6.2 Results and Discussions
Figure 6.1: Crystal structures explored in the current work. (a) Rocksalt structure
(Space Group - Fm¯3m) (b) Wurtzite structure (Space Group - P63mc)
(c) NiAs structure (Space Group - P63/mmc) (d) Zincblende structure (Space
Group - F¯43m)