Observation of photodiode and electroluminescence effects for a-C/a-C : H multilayer nanostructures on silicon

Multilayer carbon structures were obtained by alternatively depositing ultr athin amorphous carbon layers with different optical band gaps on a monocry stalline boron-doped silicon substrate. The carbon layers were grown either by magnetron sputtering (MS) of a graphite target in argon or by plasma io n-beam deposition (IBD) in cyclohexane. The current-voltage characteristics of the structures were studied and rectifying properties were shown. Furth ermore, the photodiode effect was observed in the infrared wavelength range at approximately 2 mum and photocurrent spectra were obtained. Finally, el ectroluminescence was observed in the visible range at room temperature. (C ) 2001 Elsevier Science B.V. All rights reserved.