Which scientist proposed that the photons and electrons have dual nature?

The scientist who proposed that photons and electrons have dual nature was Louis de Broglie. In his doctoral thesis published in 1924, de Broglie suggested that just as light exhibits both wave-like and particle-like behaviour (as proposed by Einstein's theory of the photoelectric effect and the wave theory of light), particles like electrons could also exhibit wave-like properties. This idea became known as wave-particle duality, and it laid the foundation for the development of quantum mechanics. De Broglie's work contributed significantly to our understanding of the behaviour of matter at the quantum level.