Abstract

A study was made of the behavior of the photoelectric efficiency of very thin films of calcium—thicknesses between 1 nm and 20 nm-when an electric field was applied to them, of intensity between 2 × 10³ V and 10⁶ V · m⁻¹, perpendicular to the plane of their substrate. The corresponding work functions and their variations in accordance with the field were determined using Fowler’s graphic method. It was seen that when the field increased, the work function relating to the normal photoelectric threshold decreased. This variation depends on the thickness of the thin film; it is greatest for a thickness d₀ of about 5.5 nm. There is a second photoelectric threshold for a thickness less than d₀ even when the field applied perpendicularly to the substrate is zero. The work function Φ_S relating to it does not vary when the field is increased. When the thickness is greater than d₀, the second threshold no longer exists for a zero applied field; it appears again when the field is higher than a certain value, which is a function of film thickness.

© 1973 Optical Society of America

Propriétés photoélectriques des couches minces de calcium

L. Gaudart and R. Rivoira
Appl. Opt. 10(10) 2336-2343 (1971)

Effect of Substrate on Radiative Properties of Thin Films

B. F. Armaly and D. C. Look
Appl. Opt. 12(8) 1904-1908 (1973)

Determination of the Optical Properties of Thin Films from Single-Angle Reflectance Measurements

D. L. Pulfrey and J. J. H. Reche
Appl. Opt. 12(7) 1577-1580 (1973)

Optical properties and electron-attenuation lengths from photoelectric-yield measurements*

E. T. Arakawa, R. N. Hamm, and M. W. Williams
J. Opt. Soc. Am. 63(9) 1131-1134 (1973)

Surface Film Thickness Determination by Reflectance Measurements

D. T. Larson, L. A. Lott, and D. L. Cash
Appl. Opt. 12(6) 1271-1275 (1973)