PHOTOCONDUCTIVITY IN N-TYPE MODULATION-DOPED GAN ALGAN HETEROSTRUCTURES/

Photoluminescence and photoconductivity data from GaN/AlGaN modulation doped heterostructures, in temperature interval between 2 and 250 K, are presented. The results show a strong influence of potential fluctu ations on both optical spectra and photo-induced transport. The electr ic field fluctuations in the interface region of the two-dimensional e lectron gas is estimated to be in the several kV cm(-1) range, suffici ent to ionize the excitons. Persistent photoconductivity effects may b e related to the same fluctuations in these structures. (C) 1998 Publi shed by Elsevier Science B.V. All rights reserved.