The optimization of n-type and p-type m-plane GaN grown on m-plane sapphire substrate by metal organic chemical vapor deposition

The properties of non-polar m-plane GaN layers grown on m-plane sapphire substrate using metal organic chemical vapor deposition at different disilane (Si2H6) and bis(cyclopentadienyl)magnesium (Cp2Mg) flow rates were investigated. The surface morphologies for Si- and Mg-doped of m-plane GaN exhibit root mean square of 1.22 and 2.95 nm, respectively. Using x-ray diffraction method, the epi-layer properties of doped m-GaN layers were studied emphasizing on the disilane and Cp2Mg flow rates towards the effect on threading dislocations and basal stacking faults. Room temperature Hall measurement indicate the maximum respective electron and hole concentration of ~1.88 × 1018 cm−3 and 6.50 × 1017 cm−3 were achieved at higher flow rate as well as the mobility of the electron. However, the mobility of hole was recorded to be low of ~5.2 cm2/V at higher Cp2Mg flow rates. The implementation of optimized n- and p-type contact layer demonstrate a 483 nm non-polar LED with light output power ~0.2 mW and forward voltage of 4.8 V at 20 mA current injection.