From the temperature dependence of electrical conductivity plotted as versus 103/ shown in Figure 5, the activation energies of films can be calculated from the slopes of the fitted lines by equation (1b), and the results are presented in Table 1 show that the activation energy increases from 0.09 eV to 0.18 eV with the increasing resistivity. With the activation energies, the temperature coefficient of resistivity (TCR) can be obtained and TCR is extensively exploited as one of the most important parameters characterizing the detectivity of uncooled IR sensors, defined as the slope of natural logarithm resistivity [20]: