A comparative study of electrical and optical properties of InN and In0.48Ga0.52N

We present results of our studies concerning electrical and optical properties of In0.48Ga0.52N and InN. Hall measurement were carried out at temperatures between T=77 and 300 K. Photoluminescence (PL) spectrum in InN and In0.48Ga0.52N. InN has a single peak at 0.77 eV at 300 K. However, the PL in In0.48Ga0.52N has two peaks; a prominent peak at 1.16 eV and a smaller peak at 1.55 eV. These two peaks are attributed to Indium segregation corresponding to a high Indium concentration of 48% and a low concentration of 36%. High electric field measurements indicate that drift velocity that tends to saturate at around Vd=1.0×107 cm/s at 77 K in InN at an electric field of F=12 kV/cm. However, in In0.48Ga0.52N the I–V curve is almost linear up to an electric field of F=45 kV/cm, where the drift velocity is Vd=1.39×106 cm/s. At applied electric fields above this value a S-type negative differential resistance (NDR) is observed leading to an instability in the current and to the irreversible destruction of the sample.