TITLE:
Photoelectric State with Long-Term Relaxation in CdTe:(Ag, Cu, Cd) and Sb2Se3:Se Photovoltaic Films
AUTHORS:
Ozodbek Ravshanboy o‘g‘li Nurmatov, Dilkhumor Tolibjonovna Mamadieva, Nosirjon Khaydarovich Yuldashev
KEYWORDS:
Thin Polycrystalline Films, Doping, Deep Centers, Anomalous Photovoltage, Photoelectret State, Long-Term Relaxation
JOURNAL NAME:
Journal of Applied Mathematics and Physics,
Vol.12 No.1,
January
18,
2024
ABSTRACT: The results of an experimental study of long-term relaxation of the photoelectret state of polycrystalline CdTe:(Ag, Cu, Cd) and Sb2Se3:Se films with an anomalous photovoltaic property are presented. In such films, the residual photovoltage is caused by the separation of photocarriers by the built-in electrostatic field of the near-surface region of space charges and their asymmetric capture by deep levels of impurities or complexes, including impurity atoms and intrinsic defects, both in the bulk and on the surface of crystal grains. It has been shown that in activated films, a two-step exponential temporary relaxation of the initial photovoltage of the order of VAPV ≈ (500-600) V is detected, and only 10% of it experiences long-term relaxation (t ≈ 100-120 min).