NOVELTY - Gallium nitride containing crystal comprises: a crystalline substrate member having a length greater than 5 millimeters; a substantially wurtzite structure characterized to be free of other crystal structures, where the other structures are less than 1% in volume in reference to a volume of the substantially wurtzite structure; an impurity concentration greater than 1015 cm-1 of at least one of lithium, sodium, potassium, rubidium, cesium, magnesium, calcium, fluorine or chlorine; and an electrical resistivity greater than 107 Omega -cm.    USE - The gallium nitride is useful: in device including a light emitting diode, laser diode, photodetector, avalanche photodiode, transistor, rectifier (a Schottky rectifier), thyristor, p-i-n diode, metal-semiconductor-metal diode, high electron mobility transistor, metal semiconductor field effect transistor, metal oxide field effect transistor, power metal oxide semiconductor field effect transistor, power metal insulator semiconductor field effect transistor, bipolar junction transistor, metal insulator field effect transistor, heterojunction bipolar transistor, power insulated gate bipolar transistor, power vertical junction field effect transistor, cascode switch, inner sub-band emitter, quantum well infrared photodetector, quantum dot infrared photodetector, solar cell, and a diode for photoelectrochemical water splitting and hydrogen generation (claimed); and as substrates for fabrication into optoelectronic and electronic devices.    ADVANTAGE - The gallium nitride is: transparent and exhibits a high-quality semi-insulating properties; and is manufactured in a cost effective manner.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for forming a group III metal nitride containing substrate comprising: providing a group III metal nitride as a source material, where the group III metal nitride is a metal comprising aluminum, gallium, or indium, and where the group III metal nitride has an oxygen content in the group III metal nitride material provided as a group III metal oxide or as a substitutional impurity within a group III metal nitride that is less than 10 parts per million; introducing the group III metal nitride source material into a chamber; adding nitrogen-containing material to the chamber; heating the chamber to a determined temperature; pressurizing the chamber to a determined pressure; processing the nitrogen-containing material with the group III metal source material in the chamber; and forming a crystalline group III metal nitride characterized by a wurtzite structure substantially free from any cubic entities and an electrical resistivity greater than 107O-cm.