Relationship between dark conductivity and temperature for amorphous HgCdTe films

The relationship between the dark conductivity (σd) and temperature (T) of amorphous HgCdTe films has been investigated at 80-300 K. The measurement of σd as a function of T indicates the presence of four distinct regions: (I) For 250K≤T<300 K(3.3<1000/T≤4.0), σd is strongly increase with T increasing, the transport mechanism is dominated by extended state conduction, (II) for 180K≤T<250 K(4<1000/T≤5.6), σd is linearly increase with T increasing, hopping conduction between localized band tail state dominates the transport mechanism, (III) for 120K≤T<180K (5.6<1000/T≤8.3), σd is very small and weakly increase with T increasing, constant-range hopping conduction in localized states near the Fermi energy significantly contributes to the transport properties, and (IV) 80K≤T<120K (8.3<1000/T≤12.5), the dark conductivity of amorphous HgCdTe films is very small and weakly decreases with temperature increasing, it would be possible that the conductivity type of amorphous HgCdTe films converted about 120K, i.e. from the n type converted to p type. The temperature behavior of σd of amorphous HgCdTe was described in terms of the Mott-Davis model. © 2009 SPIE.