Cilmo, Marco (2015) Development of a Carbon Nanotubes Based Photodetetor. [Tesi di dottorato]

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Item Type: Tesi di dottorato
Lingua: English
Title: Development of a Carbon Nanotubes Based Photodetetor
Creators:
CreatorsEmail
Cilmo, Marcomarco.cilmo@gmail.com
Date: 31 March 2015
Number of Pages: 176
Institution: Università degli Studi di Napoli Federico II
Department: Fisica
Scuola di dottorato: Scienze fisiche
Dottorato: Tecnologie innovative per materiali, sensori ed imaging
Ciclo di dottorato: 26
Coordinatore del Corso di dottorato:
nomeemail
Cassinese, Antoniocassinese@fisica.unina.it
Tutor:
nomeemail
La Rana, GiovanniUNSPECIFIED
Osteria, GiuseppeUNSPECIFIED
Date: 31 March 2015
Number of Pages: 176
Uncontrolled Keywords: Carbon nanotubes, photodetectors.
Settori scientifico-disciplinari del MIUR: Area 02 - Scienze fisiche > FIS/03 - Fisica della materia
Area 02 - Scienze fisiche > FIS/04 - Fisica nucleare e subnucleare
Aree tematiche (7° programma Quadro): NANOSCIENZE, NANOTECNOLOGIE, MATERIALE E PRODUZIONE > Nanoscienze e Nanotecnologie
NANOSCIENZE, NANOTECNOLOGIE, MATERIALE E PRODUZIONE > Nuove produzioni
Date Deposited: 07 Apr 2015 14:00
Last Modified: 01 Oct 2015 17:20
URI: http://www.fedoa.unina.it/id/eprint/10351
DOI: 10.6092/UNINA/FEDOA/10351

Abstract

The purpose of this PhD thesis has been the development of a new solid-state photodetector based on carbon nanotubes grown on doped silicon substrates. Carbon nanotubes films can be easily grown on large area creating large photocathode with unique and precious characteristics: low cost, high quantum efficiency, high linearity, and stable at room temperature. It has been demonstrated that the heterojunction created between a film of carbon nanotubes and silicon generates a light sensitive detector with good quantum efficiency in the visible range. In fact, the carbon nanotubes layer absorbs photons producing electron-hole pairs that can be separated by the carbon nanotubes film and the electrical field inside the depletion zone of the heterojunction. The charge produces a photocurrent drained out by the applied voltage. It was found that dark current measurements are well explained by assuming that the charge transport is controlled by tunneling between carbon nanostructures and silicon. Starting from this observation, a first model has been proposed. In order to simulate the devices behavior, we started with an equivalent circuit: once the parameter values are fixed we are able to reproduce the current-voltage characteristics, both in dark conditions and under illumination for different light intensities. After the characterization and the study of the first group of photodetectors, a series of silicon substrates have been made, some with internal junctions in the order to obtain an internal amplification. The surprising result of this research has been that substrates with internal junctions and covered with carbon nanotubes do not showed mechanisms of internal charge multiplication, but simple substrates and without internal junctions have shown mechanisms of charge multiplication. This phenomenon probably is due to the presence of the film of carbon nanotubes.

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