Where is the better Gallium phosphide

Where is the better Gallium phosphide? For many people this is a strange object, and here's the introduction to it:

Gallium nitride is a kind of by Ⅲ elements gallium (Ga) and V elements phosphorus (P) synthetic Ⅲ - V compound semiconductor materials. Gallium nitride crystal structure of sphalerite, lattice constant 5.447 + / - 0.06, chemical bond and the mixture of covalent bond, the ionic bond component is about 20%, at 300 k energy gap of 2.26 eV, belong to indirect transition type semiconductor. Gallium phosphide and other broadband gap Ⅲ - Ⅴ family compound semiconductor (e.g., GaAS, InP), the same can by introducing deep center make the Fermi level close to the central band gap, such as adding impurity elements such as chromium, iron, oxygen can be half insulating materials.