This paper describes the properties of surface‐barrier photocells on silicon. In particular, data are given on photocurrent versus light intensity, photocurrent versus reverse bias voltage, open‐circuit photovoltage versus light intensity, open‐circuit photovoltage versus wavelength of light, open‐circuit photovoltage versus temperature, and photocurrent versus temperature. An interesting multiplication effect of optically excited carriers is observed at lower temperatures. The theory of the surface‐barrier photoeffect is further generalized.