1960 年 29 巻 6 号 p. 412-420
Thin luminescent films of several useful phosphors are formed upon adequate substrates in two steps: vacuum evaporation followed by post firing in suitable atmospheres. Among the phosphors, ZnS:Cu:Cl powder samples of various Cu concentrations are prepared and the relation of the relative intensity of their blue and green emissions to the Cu concentration is examined. The luminescence properties are investigated by the excitation with highly accelerated electron beam. From the experimental results about emission spectra, decay curves, and dependences of, the luminescence intensity upon beam current density and accelerating voltage, the following are presumed.
The luminescence centers of the films are the same as those of their parent powder phosphors, and by the post firing, nearly amorphous states and non-uniform constitution of the evaporatedd films are recovered to nearly the same crystalline states and uniform constitution, as of the powder phosphors.
The penetration range of electron beam through phosphors can be determined from the: linear-dependency of luminescence intensity of the films uopn the accelerating voltage, The- following, formulas are obtained as the relation between the penetration range through solids and the energy-of electron beam, i.e., R=1.6×10-6×V1.6 for CaWO4 and R=2.0×10-6×V1.6 for ZnS. (R and V are in cm and in kV, respectively) Their results, which might have been influenced by secondary products such as secondary electron, are compared with the outcome of Thpmson-Whiddingtons law.