Study of the blue luminescence in unintentional doped GaN films grown by MOCVD

Optical and structural studies of GaN 3D structures selectively grown by MOCVD

“…The 370-650 nm bands are in accordance with common optical results for GaN. In fact, its optical response is made up of three bands: near band-edge, blue band, and a large yellow band [27][28][29][30]. Although the precise mechanisms of these transitions are still being debated, defects and impurities can influence the emission [28][29][30][31].…”

“…The peak in the near bandedge in the UV region could be due to excitonic emission at RT, as proposed by Jin et al [28]. In the blue band, the emission could arise from two mechanisms: DA transition or free electron-acceptor (eA) transitions [30,31]. Oxygen is supposed to be responsible for shallow-donor energy bandgap level, whereas carbon is an acceptor [17,29].…”

“…In fact, its optical response is made up of three bands: near band-edge, blue band, and a large yellow band [27][28][29][30]. Although the precise mechanisms of these transitions are still being debated, defects and impurities can influence the emission [28][29][30][31]. The peak in the near bandedge in the UV region could be due to excitonic emission at RT, as proposed by Jin et al [28].…”

“…These two impurities can be responsible for the DA pair observed emission [17]. In the eA mechanism, the involved energy levels can be a conduction band and acceptor level [30]. Gallium vacancies are candidates for a deep acceptor-level emission [31].…”

Growth of vanadium-doped GaN by MOVPE

“…However, the 2.6 eV emission intensity increases with the increasing of the VCl 4 flow rate. Then, we can believe that the 2.6 eV band was not due to O. Shuti et al [34] have assigned the 2.9 eV emission to some intrinsic defects. The presence of the Cl radicals in the vanadium source induces the formation of volatile species (GaCl, GaCl 2 , GaCl 3 , etc).…”