Characteristics of In_xGa_{1 - x}N/GaN grown by LPMOVPE with the variation of growth temperature

We have studied the growth of In_xGa_{1 - x}N/GaN on (0 0 0 1) sapphire substrates. The films were grown in a horizontal MOVPE reactor at the reduced pressure of 100 Torr. In composition, x in In_xGa_{1 - x}N/GaN grown at 810°C determined by the DCXRD is 0.08 and 0.13 for 770°C. The FWHMs of the DCXRD for (0 0 0 2) diffraction from the In_0.08Ga_0.92N and In_0.13Ga_0.87N are 11 arcmin and 9 arcmin, respectively, whose difference is considered to be resulted from In dissociation. In addition, we confirmed that the thermal pit density of In_0.08Ga_0.92N was higher than that of In_0.13Ga_0.87N with the SEM observation. The carrier concentration and mobility of In_0.08Ga_0.92N are 3 × 10¹⁸/cm³ and 47 cm²/V s, and those of In_0.13Ga_0.87N are 9 × 10¹⁸/cm³ and 70 cm²/V s, respectively. In spite of the lower carrier concentration, the mobility of In_0.08Ga_0.92N is lower than that of In_0.13Ga_0.87N, which is considered to be due to the higher defect density of In_0.08Ga_0.92N than that of In_0.13Ga_0.87N as can be seen from the result of DCXRD. The FWHMs of band-edge emission peak measured by PL at room temperature were 110 meV at 395 nm for In_0.08Ga_0.92N and 120 meV at 410 nm for In_0.13Ga_0.87N. The In composition in InGaN increased as the growth temperature decreased, and In was still dissociated at 770°C. Some high-quality InGaN films were grown on GaN films compared with the recent results of others.