Walther Bothe's contributions to the understanding of the wave-particle duality of light

It is little known that during the birth of quantum mechanics Walther Bothe (1891-1957) published from mid-1923 to the end of 1926, partly together with Hans Geiger (1882-1945), as many as 20 papers, all dealing with light quanta (photons). Around half of the publications (11) are of experimental nature; the rest deal with theoretical problems. This paper presents Walther Bothe's experimental and theoretical contributions to the understanding of the particle-wave duality of light in the mid-1920s, for which the interplay between experimental and theoretical ideas plays an essential role.