Effect of annealing temperature on a polycrystalline lead oxide film derived by using the sedimentation method

Polycrystalline PbO has a low effective work function, a high atomic number and the possibility of large-area deposition. In this research, fine lead-oxide particles were synthesized using a solution-combustion method, and PbO films of 200 μm in thickness were deposited by a special wet sedimentation coating process at room temperature. The influences of annealing temperature on the X-ray detection properties of the film were investigated in detail. From the experimental results, the dark current was stable in about 0.4 second at a 500 .deg. C annealing temperature, but with no annealing, several tens of seconds were required for dark-current stability. In addition, the dark current density decreased rapidly with increasing annealing temperature, and the value was below 2 nA/cm2 after 300 .deg. C annealing. The X-ray sensitivity was about 2 ∼ 4 nC/mR-cm2 at 500 .deg. C annealing and this value is higher by 10 time than that of a commercial 500 μm a-Se film. Finally, the signal loss of the 300 ∼ 500 .deg. C annealed sample was lower by 2% at five continuous X-ray exposures.