Lichtelektrische Leitung und Polarisation durch Laserstrahlung im Volumen von ZnO-Kristallen

Abstract

In the volume of ZnO-single crystals a high concentration of free electrons was generated by two-photon absorption of ruby laser pulses. With regard to the different lifetimes of the moved electrons parallel and perpendicular to thec-axis influenced charges could be measured, which result only from the thermal motion of the electrons. With an applied voltage the Schubweg per unit electric field (called range) was investigated as a function of the concentration of absorbed photons. During irradiation with the laser pulse a pressure wave is caused by the thermal diffusion of the electrons; the arrival of the pressure wave on the electrodes in thec-direction was measured by the piezoelectric effect.