Irradiation of the metallic and semiconductor materials with laser pulses results in the generation of a photocurrent, which depends on the polarization and angle of incidence of the laser beam. Investigation of polarization-sensitive photocurrent will have increasingly importance for future optoelectronics being especially promising for development of polarization-sensitive photosensors. The Thesis is devoted to the investigation of the polarization sensitive photoresponse of silver-palladium (Ag/Pd) nanocomposite films, in the ultraviolet, visible, and infrared spectral ranges at nanosecond and femtosecond excitation. It was shown that the phase composition of the Ag/Pd films depends on fabrication temperature, which determines electronic and photovoltaic properties of the films. Based on results of experiments we found that the photocurrent in Ag/Pd films originates from the photon drag and surface photogalvanic effects.
The pronounced dependence of the photocurrent on the angle of incidence and polarization of excitation beam open avenues towards development of new position-sensitive sensors for industry and space applications. On the other hand the materials generating polarization-sensitive photocurrent can become the base of high-speed light polarization analyzers which can find application in the optical communication and data processing where the state of polarization can be used for data coding.
The doctoral dissertation of MSc Aleksandr Saushin, entitled Polarization-sensitive photoresponse of metal-semiconductor nanocomposite film will be examined at the Faculty of Science and Forestry on the 4th of December in Joensuu and online. The opponent in the public examination will be Professor Zhipei Sun, Aalto University, and the custos will be professor Yuri Svirko, University of Eastern Finland. The public examination will be held in English.
