TY - JOUR AU - Prof. V. Etkin PY - 2026 DA - 2026/03/10 TI - The Quantum of Radiation or A Threshold of Action? JO - Japan Journal of Research VL - 7 IS - 2 AB - This article refutes the assertion, based on an examination of the photoelectric effect, that Planck's constant is universal, as well as the quantum mechanics that underlies it. Several errors in the energy balance equation for the photoelectric effect are revealed. It is shown that the quantum yield influences Planck's constant. The need to account for the efficiency of photovoltaic energy converters (PVCs) and their relationship to quantum yield is substantiated. The true meaning of a radiation quantum as the energy required to maintain the "idle" state of a PVC is established, along with its dependence on the type of photocathode and its operating mode. Based on this, a classical explanation is given for the laws of the photoelectric effect discovered by A. Stoletov, and the conclusion is drawn that it is erroneous to contrast it with the laws of quantum mechanics. SN - 2690-8077 UR - https://dx.doi.org/10.33425/2690-8077.1226 DO - 10.33425/2690-8077.1226