NOVELTY - Photoelectric conversion device (1) comprises a layered structure including photoelectric conversion semiconductor layer (30) for generating an electric current when it absorbs light. A concentration distribution of alkaline(-earth) metal in the photoelectric conversion semiconductor layer in a thickness direction comprises a valley position with a lowest concentration of alkaline(-earth) metal and an area with a concentration of alkaline(-earth) metal higher than the concentration at the valley position, where the area is nearer to a substrate (10) from the valley position.    USE - Photoelectric conversion device used for a solar battery (claimed) and infrared sensors.    ADVANTAGE - The device has an optimized concentration distribution of alkaline(-earth) metal in photoelectric conversion layer in the thickness direction, has less defects causing a loss in photoelectric conversion in the photoelectric conversion layer, and thus has high photoelectric conversion efficiency. The amount of alkaline(-earth) metal to be supplied and the state of diffusion are optimized, and thus highly efficient photoelectric conversion devices can be provided in a stable manner. The photoelectric conversion semiconductor layer has high light absorption rate and high photoelectric conversion efficiency.    DETAILED DESCRIPTION - Photoelectric conversion device (1) comprises a layered structure formed on a substrate, and comprising a first electrode (20), a photoelectric conversion semiconductor layer (30) for generating an electric current when it absorbs light, and a translucent second electrode (50). The photoelectric conversion semiconductor layer comprises, as a main component, compound semiconductor(s) comprising group IB element, group IIIB element, and group VIB element; and alkaline(-earth) metal(s). A concentration distribution of alkaline(-earth) metal in the photoelectric conversion semiconductor layer in a thickness direction comprises a valley position with a lowest concentration of alkaline(-earth) metal and an area with a concentration of alkaline(-earth) metal higher than the concentration at the valley position, where area is nearer to the substrate from the valley position. Expressions relating the concentration of the alkaline(-earth) metal at the valley position, and highest concentration of alkaline(-earth) metal, i.e. a (mol/cm3)=1.0x 10-6-2.0x 10-5 and b/a=1.5-4.0 are satisfied, where a (mol/cm3) is the concentration of alkaline(-earth) metal at the valley position, and b (mol/cm3) is the highest concentration of alkaline(-earth) metal at a position nearer to the substrate from the valley position. An INDEPENDENT CLAIM is included for production of photoelectric conversion device.    DESCRIPTION OF DRAWING(S) - The drawing is a sectional view of photoelectric conversion device.    Photoelectric conversion device (1)    Substrate (10)    First electrode (20)    Photoelectric conversion semiconductor layer (30)    Translucent second electrode (50)