Abstract
This paper presents low-temperature measurements of magnetoresistivity in heavily doped n-type GaN grown by basic GaN growth technologies: molecular beam epitaxy, metal-organic vapor phase epitaxy, halide vapor phase epitaxy and ammonothermal. Additionally, GaN crys-tallized by High Nitrogen Pressure Solution method was also examined. It was found that all the samples under study exhibit negative magnetoresistivity at low temperature (10 K < T < 50 K) and for some samples this effect is observed up to 100 K. This negative magnetoresistivity effect is analyzed in the frame of the weak localization phenomena in the case of three-dimensional electron gas in a highly doped semiconductor. This analysis allows to determine the phasing coherence time τφ for heavily doped n-type GaN. The obtained τφ value is proportional to T-1.34, indicating that the electron–electron interaction is the main dephasing mechanism for the free carriers.