Properties of Si-doped a-plane GaN grown with different SiH₄ flow rates

Nonpolar Si-doped α-plane GaN layers were grown using metal organic chemical vapor deposition (MOCVD) with different silane (SiH₄) flow rates. The on-axis full width at half maximum (FWHM) of X-ray rocking curves (XRCs) along the c-and m-axis directions showed that Si doping barely affected the anisotropy of α-plane GaN. A decrease in the edge threading dislocations (TDs) with increasing Si doping was confirmed by the decreased off-axis FWHM values of the XRCs. With increasing SiH₄ flow rate, both the carrier concentration and mobility increased through a reduction in the edge dislocation density. The photoluminescence (PL) spectra revealed that the PL peak positions were first slightly redshifted and then blueshifted with increasing carrier concentration.