Who among the following has explained the phenomenon of photoelectric effect?

The photoelectric effect is a phenomenon where electrons are emitted from a metal surface when illuminated by light of sufficient frequency. While Max Planck introduced the concept of energy quanta to explain blackbody radiation, it was Albert Einstein who extended this hypothesis in 1905 to explain the photoelectric effect. Einstein proposed that light consists of discrete packets of energy called photons (or light quanta), where the energy of each photon is proportional to its frequency. This explanation resolved the failures of the classical wave theory, which could not account for the existence of a cutoff frequency or why electron energy depended on frequency rather than intensity. For this groundbreaking work, which laid the foundation for quantum mechanics, Einstein was awarded the Nobel Prize in Physics.