## 1 Introduction  
Much attention is given to studying charge transfer and electronic excitation in the overlayers of real metallic surfaces in relation to various problems in tribology, lubrication, adhesion, corrosion, and so on [1; 2]. The present study reveals the effects of temperature, photon energy, and surface overlayer on photoelectron emission (PE) from scratched iron surfaces. PE takes place when photons are absorbed by electrons, reaching the release of these photon-absorbing electrons from the surface. The theoretical basis of PE is well expressed by [PERSON]'s three-step model [3]. This divides the photoemission into three successive steps: (a) optical excitation, (b) transport of photo-excited electrons to the surface, and (c) release of excited electrons into a vacuum. In addition, the parameters of the emitter, such as the optical absorption coefficient, electron-electron scattering mechanisms, and height of the potential barrier at the surface [4] are also related to this theory. For real iron surfaces, however, electron emission at low temperature close to room temperature is very weak even in response to irradiation by photons with energy greater than the work function of the metal. This observation can be attributed to the effect of the surface overlayer. This film is formed by adsorbed species, such as oxides, hydroxyl groups, reaction products, and carbon materials, as a result of the interaction of the metal with the environment. Information known about the temperature dependence of the transfer of electrons photo-excited from the metal base through superficial layers is limited, owing to the difficulties related to experimental measurements of such electrons. We developed a non-vacuum-based method to examine the influence of temperature and incident light wavelengths (photon energies) on PE from real iron surfaces. In the present study, for sample surfaces scratched in the environments such as air, water, and liquid organics, the PE results obtained from the PE measurement, carried out in two ways as a function of temperature and light wavelength, were reexamined in more detail in relation to the X-ray photoelectron spectroscopy (XPS) results. In the first case, for real iron surfaces scratched in air, water, and liquid organic environments, we outlined the results of PE previously reported, often called thermally assisted photoelectron emission (TAPE) [5], as well as the results of XPS. The experiments were carried out to examine the influence of the interaction between mechanical deformed metal surfaces and the environments on the PE behavior of the surfaces. Mechanical deformation was conducted by scratching sample surfaces with a diamond cutter in seven environments such as air, benzene, cyclohexane, water, methanol, ethanol, and acetone. Then, the intensity of PE was measured as a function of temperature under 210-nm-wavelength light irradiation using a modified Geiger counter. Temperature was swept in the 25-339 \({}^{\circ}\)C range in two cycles of temperature increase and subsequent reduction. The first cycle was called Up1 and Down1 scans, while the second cycle was called Up2 and Down2 scans. Here, Up and Down mean temperature increase and temperature decrease, respectively. Four PE glow curves, expressing the PE intensity as a function of temperature, were obtained for a scratched sample [6]. The PE glow curve obtained in the Up1 scan was found to be strongly affected by the environment in which scratching was performed, while those obtained in the following three scans took a similar trend and were almost independent of the environment. For the above-scratched iron samples, we obtained the activation energies from the glow curves of PE quantum yield (emitted electrons per incident photon), \(Y\), during four temperature scans under 210-nm-wavelength light irradiation and reported their relationship with the acid-base interaction between molecules of the liquid environments and Fe-OH on the surface [5].