Question: what is the difference between 12-16 and 13-15 compounds?
Answer: Group 13-15 compounds such as AIP, GaAs, etc. have large covalent character but Group 12-16 compounds such as ZnS, CdS, HgTe, etc.do not have perfect covalent bonds but posses sufficient ionic character. ... Howver, all of them are semiconductors.