1887: Heinrich Hertz published, “On an effect of UV light upon the electric discharge” (Sitzungsber d. Berl. Akad. d. Wiss., June 9, 1887).
1895: Discovery of X-rays by W.K. Röntgen.
1897: J.J. Thomson’s cathode ray tube experiments for measuring e/m of electrons: a primitive electron spectrometer.
1905: Einstein equation for the photoelectric effect :eV = hυ − φ.
1907: Innes, a Ph.D. student, conducted research on: “….the velocity of the cathode particles emitted by various metals under the influence of Röntgen rays….” (Proc. Roy. Sec.. Ser. A 79, 442(1907)). A photographic plate was used to measure the deflection of photoelectrons in a magnetic field.
1918: First XPS paper by a Harvard University researcher, Mang-Fuh Hu, reported, “some preliminary results in a determination of the maximum emission velocity of the photoelectrons from metals at X-ray frequencies” (Phys. Rev. 11, 505(1918)).
1925: H. Robinson, a pioneer who devoted his entire research career to XPS, wrote that, “…an accurate knowledge of the energies associated with the different electronic orbits within the atoms is essential to the further development of the theory of atomic structure” (Proc. Roy. Sec., Ser. A, 104, 455(1923)).
1950: R.G. Steinhardt Jr. published his PhD thesis, “An X-ray photoelectron spectrometer for chemical analysis” (Leihigh University). He was also the first to recognize that “X-ray photoelectron spectra are profoundly influenced by the chemical and physical nature of the surface under investigation” (Anal. Chem. 25, 697(1953)).
1954: Kai Siegbahn built his high resolution photoelectron spectrometer, and subsequently established XPS as an important research and analysis tool. (Figure 3.2.2 from K. Siegbahn, C. Nordling, A. Fahlman, R. Nordberg, K. Hamrin, J. Hedman, G. Johnsson, T. Bergmark, S. E. Karlsson, I. Lindgren, and B. Lindberg, Nova Acta Regiae Soc. Sci. Ups. 20, 7 (1967).)
In 1981: Kai M. Siegbahn was awarded the Nobel Prize for “his contribution to the development of high-resolution electron spectroscopy”. (Nobel Lectures in physics (1981-1990), World Scientific Publishing Co. Pte. Ltd 1993)
Information is used from http://www.phy.cuhk.edu.hk/course/surfacesci/mod3/m3_s1.pdf