Temperature Dependence of the Miscibility Gap on the GaN-Rich Side of the Ga–N–As System

Molecular beam epitaxy of crystalline and amorphous GaN layers with high As content

“…The highest concentrations reported in MOVPE layers is x$0.067 [3,6] and in MBE layers are x$0.0026 [7] grown at 750 1C and x$0.01 [8] at 500 1C, respectively. The As solubility limit in GaN 1Àx As x alloys is increasing with decreasing growth temperature [8,9].…”

Arsenic incorporation in GaN layers grown by metalorganic chemical vapor deposition

“…And then extra As adatoms over $5 Â 10 19 cm À 3 would compete with N adatoms and limited As adatoms could be incorporated on N-sites of GaNAs. According to Foxon et al, weak and broad emission from GaNAs layer was observed around 2.7 eV, and they believed that its luminescence came from As Ga double donor in GaN [6][7][8]. In order to check whether our GaNAs also gives As double donorrelated emission or not, luminescence properties of all samples in Fig.…”

“…Even if bandgap energy of GaN, 3.4 eV, could be lowered to 2.3 eV for green emission by incorporating As atoms over 3% in GaN, it is extremely difficult to incorporate sufficient As atoms in GaN to gain large bandgap lowering as predicted theoretically. Reports on As incorporation in GaN by Foxon et al focused just on GaN:As with low As concentration, 10 17 -10 19 cm À 3 [6][7][8], which was quite different situation from GaNAs with 1 As atomic %. Therefore, it is very important to understand how As atoms are incorporated in GaN.…”

“…When GaNAs layers were grown at higher temperature for better crystalline quality, As atoms was not alloyed but doped in GaN below 10 19 cm À 3 . But weak emissions from those GaNAs layers were observed around 2.7 eV, and it was believed that its photoluminescence came from As Ga substitutional defects which acted as double donors in GaN [6][7][8]. Even if bandgap energy of GaN, 3.4 eV, could be lowered to 2.3 eV for green emission by incorporating As atoms over 3% in GaN, it is extremely difficult to incorporate sufficient As atoms in GaN to gain large bandgap lowering as predicted theoretically.…”