Method for the characterization of electron, light- and heavy-hole concentrations and mobilities in narrow-gap p-type HgCdTe

A novel simple characterization method based on magnetotransport measurements has been developed to unambiguously determine the electrical parameters of the electrons, light and heavy holes in the narrow-gap p-type HgCdTe (x~0.2). No mathematical fitting procedure is required in this method for reliably calculating the mobility and density of each type of carrier. The technique comprises simultaneous measurements of the Hall coefficient RH and magnetoresistance at five values of the low magnetic flux density B and the conductivity σ at B = 0. This method allows the determination of the electron, light- and heavy-hole mobilities and concentrations at temperatures below 77 K, where the dependence RH(B) is positive and the bulk mixed-conduction regime still takes place. When the electrons freeze out at low temperatures, the parameters of heavy and light holes can be determined by measuring three values of Hall coefficient and magnetoresistance. It has also been shown that a more accurate value of heavy-hole mobility can be obtained by multiplying together RH and σ measured at the high magnetic field at which the transverse magnetoresistance becomes saturated. The simple equations have been derived for the electron and light-hole mobilities and concentrations from the measurement of the differential magnetoresistance. The developed method has been employed for the experimental determination of electron, light- and heavy-hole parameters in p-type HgCdTe (x~0.2).