Space-charge electric field in photorefractive multiple quantum wells

Abstract

We have developed a graphical method to determine the space-charge electric field in photorefractive multiple quantum wells when the photocurrent is dominated by the drift current. The minima and maxima of the space-charge electric field due to space modulated light intensity are obtained from photocurrent measurements under uniform illumination. In addition, we find that the space-charge field depends nonlinearly on the applied electric field and the intensity of light, and changes sharply with the intensity up to a critical intensity beyond which it remains unchanged.