The GaN/substrate bi layer may be cooled from the growth temperature to {HEAD ~ an ambient temperature}, wherein {TAIL ~ GaN material cracks} laterally and separates from the substrate, forming a free standing article 
wherein
The GaN / substrate bi layer may be cooled from the growth temperature to { HEAD ~ an ambient temperature } , wherein { TAIL ~ GaN material cracks } laterally and separates from the substrate , forming a free standing article
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH