Effects of Different Amounts of Surfactant on Characteristics of Sol-Gel Dip Coated Gallium Nitride Thin Films

Abstract

In the present study, sol-gel dip coating method was used to synthesize GaN thin films. Gallium nitrate hydrate (Ga(NO3)3.xH2O) powder and ethanol were used to prepare the precursor solution and diethanolamine (DEA) was added as stabilizer. Different amount of DEA were added into the gallium nitride (GaN) precursor at 0 ml, 0.10 ml, 0.25 ml, 0.50 ml, 0.75 ml and 1.0 ml respectively. The effects of different amounts of DEA on GaN thin films on structural and optical properties of the GaN films were studied. The high resolution X-ray diffraction results revealed that the deposited GaN thin films have hexagonal wurtzite structure with (002) preferred orientation. The intensity of the GaN (002) diffraction peaks increases with the increase of amount of surfactant from 0 ml to 0.75 ml and degraded at 1.0 ml. The Raman signal of E2 (high) GaN peaks increases and becomes stronger at 0.75 ml. Further increase in the amount of surfactant has caused the intensity of E2 (high) GaN peak decreases. The measured results show that the amount of surfactant exerts a strong influence in improving crystallinity of GaN thin films.