Effect of the Copper Content on the Kinetics of the Microwave Photoconductivity of CIGS Solid Solutions

Abstract

The kinetics of the photoresponse of microwave photoconductivity (9 GHz, TE₁₀₁-type cavity) on excitation by laser light pulses with a wavelength of 337 nm and a duration of 8 ns in copper-deficient Cu_{1 –x}(In_0.7Ga_0.3)Se₂ (CIGS) (0 < x ≤ 0.4) solid solutions with the chalcopyrite structure is investigated in a wide light intensity range. With an increase in the laser radiation density to ~5 × 10¹⁴ photon/cm² per pulse, the photoresponse acquires, along with the previously revealed skin effect, the effect of the filling of traps created by V_Cu vacancies and Cu⁺² · V_Cu defect associates, the concentration of which increases with a decrease in x in the CIGS formula.