Electrical Transport in Wurtzite and Zincblende

In contrast to our good understanding of the electrical properties of n-type, wurtzitic GaN, knowledge of these properties in p-type wurtzitic GaN, or in zincblende GaN of either n- or p-type, is much poorer. As discussed below, serious questions and discrepancies exist in the literature concerning these materials. 

It is often instructive to plot resistivity p versus 1/T in order to get a qualitative picture of electrical behaviour. In FIGURE 1, we compare p versus 1/T data for layers grown by MBE, MOCVD and HVPE. 

These particular samples were chosen for comparison, because each has excellent optical characteristics, with exciton linewidths of 5 meV or less. 

Beginning at high T (low 1/T), p at first decreases, due to an increase in p, then increases, due partially to a decrease in p but mostly due to the electrons freezing out on the donors, and finally increases again but with a much lower activation energy 

FIGURE 1 Resistivity versus temperature for MBE, MOCVD and HVPE GaN on sapphire. 

---

A3.5 Time-resolved photoluminescence studies of GaN A3.6 Persistent photoconductivity in GaN A3.7 Electrical transport in wurtzite and zincblende GaN A3.8 Characterisation of III-V nitrides by capacitance transient spectroscopy... 

---