Carbon nanotube Schottky type photodetectors for UV applications

Multiple wall carbon nanotubes (MWCNT) present advantages for optoelectronic applications such as the large effective photo-collector surface as well as the possibility to tune their band gap and absorbance through the growth parameters. We demonstrate a hybrid MWCNT/Si3N4/n-Si photodetector based on ordered MWCNTs and evaluate its performance in the UV, visual and near IR spectrum (200-1000 nm). The basic device and some meaningful variations including additional layers are electrically and optically tested and compared. The overall results suggest that all devices had a satisfactory performance in the visual part of the spectrum and that the basic structure had the better performance as a UV detector (EQE 90% @ 275 nm@ 7 V). The aim of this work is to demonstrate that the growth of dense ordered MWCNTs can be successfully combined with other semiconductor clean room processes in order to fabricate photodetectors, provided that the side effects are taken into account and the process flow is selected appropriately.