화학공학소재연구정보센터
Applied Surface Science, Vol.187, No.3-4, 179-186, 2002
Photodissolution of cleaved CdTe(110): atomic force microscopic and Auger electron spectroscopic study
Presented is the morphological evolution of cleaved CdTe(l 10) during photodissolution in 0.1 M Na2SO4 solution. The surfaces of the photodissoluted CdTe(1 10) were imaged with an atomic force microscope, and the morphological variation was found to depend on the illumination level. The CdTe(l 1 0) surfaces photodissolved under illumination of -0.6 mW/cm(2) were covered with homogenously distributed pits and protrusions, and such a morphology was observed consistently within the experimental time scale (2 h). During photodissolution under similar to7 mW/cm(2) illumination, however, the morphology varied in a cyclic manner: pit-plateau-protrusion. It has also been found that after two photodissolution cycles, the surface did not show any apparent cyclic behavior. The compositional change of the CdTe(l 10) surface illuminated at similar to7 mW/cm(2), measured with an Auger electron spectrometer, was observed to correlate with the morphological variation, as well. Based on the correlation of the morphology and composition, the period of the photo dissolution cycle under similar to7 mW/cm(2) was estimated to be 30 min. The morphological cyclic variation of cleaved CdTe(I 10) surface during photodissolution is interpreted in terms of local Te enrichment. (C) 2002 Elsevier Science B.V. All rights reserved.