Abstract

Capacitance of capacitors in which one or both platesare made of a two-dimensional charge system (2DCS) can be increasedbeyond their geometric structural value. This anomalouscapacitance enhancement (CE) is a consequence of manipulationof quantum mechanical exchange and correlation energies in theground state energy of the 2DCS. Macroscopically, it occurs atcritical charge densities corresponding to transition from an interacting"metallic" to a noninteracting "insulator" mode in the 2-Dsystem. Here, we apply this concept to a metal-semiconductor-metal capacitor with an embedded two-dimensional hole system(2DHS) underneath the plates for realization of a capacitancebasedphotodetector. Under sufficient illumination, and at criticalvoltages the device shows a giant CE of 200% and a peak-tovalleyratio of over 4 at probe frequencies larger than 10 kHz.Remarkably, the light-to-dark capacitance ratio due to CE atthis critical voltage is well over 40. Transition of the 2DHSfrom insulator to metallic, enforced by charge density manipulationdue to light-generated carriers, accounts for this behavior,which may be used in optical sensing, photo capacitors, and phototransistors.

Autore Pugliese

• Cola Adriano , Persano Anna , Quaranta Fabio

Tutti gli autori

• Dianat P.; Persano A.; Quaranta F.; Cola A.; Nabet B.

Titolo volume/Rivista

IEEE journal of selected topics in quantum electronics

Anno di pubblicazione

2015

ISSN

1077-260X

ISBN

Non Disponibile

Numero di citazioni Wos

Nessuna citazione

Ultimo Aggiornamento Citazioni

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Numero di citazioni Scopus

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Ultimo Aggiornamento Citazioni

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Settori ERC

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Codici ASJC

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