Photoexcited-induced sensitivity of InGaAs surface QDs to environment

Milla Rodrigo, María José and Ulloa Herrero, José María and Fernández González, Alvaro de Guzmán (2014). Photoexcited-induced sensitivity of InGaAs surface QDs to environment. "Nanotechnology", v. 25 (n. 44); pp. 1-6. ISSN 0957-4484. https://doi.org/10.1088/0957-4484/25/44/445501.

Description

Title: Photoexcited-induced sensitivity of InGaAs surface QDs to environment
Author/s:
  • Milla Rodrigo, María José
  • Ulloa Herrero, José María
  • Fernández González, Alvaro de Guzmán
Item Type: Article
Título de Revista/Publicación: Nanotechnology
Date: 2014
ISSN: 0957-4484
Volume: 25
Subjects:
Freetext Keywords: Quantum dots, surface states, photoexcitation, humidity sensors, adsorption
Faculty: Instituto de Sistemas Optoelectrónicos y Microtecnología (ISOM) (UPM)
Department: Otro
Creative Commons Licenses: Recognition - No derivative works - Non commercial

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Abstract

A detailed analysis of the impact of illumination on the electrical response of In0.5Ga0.5As surface nanostructures is carried out as a function of different relative humidity conditions. The importance of the surface-to-volume ratio for sensing applications is once more highlighted. From dark-to-photo conditions, the sheet resistance (SR) of a three-dimensional In0.5Ga0.5As nanostructure decays two orders of magnitude compared with that of a two-dimensional nanostructure. The electrical response is found to be vulnerable to the energy of the incident light and the external conditions. Illuminating with high energy light translates into an SR reduction of one order of magnitude under humid atmospheres, whereas it remains nearly unchanged under dry environments. Conversely, lighting with energy below the bulk energy bandgap, shows a negligible effect on the electrical properties regardless the local moisture. Both illumination and humidity are therefore needed for sensing. Photoexcited carriers can only contribute to conductivity if surface states are inactive due to water physisorption. The strong dependence of the electrical response on the environment makes these nanostructures very suitable for the development of highly sensitive and efficient sensing devices.

Funding Projects

TypeCodeAcronymLeaderTitle
Madrid Regional GovernmentP2009/ESP-1503UnspecifiedUnspecifiedUnspecified

More information

Item ID: 38814
DC Identifier: http://oa.upm.es/38814/
OAI Identifier: oai:oa.upm.es:38814
DOI: 10.1088/0957-4484/25/44/445501
Official URL: http://iopscience.iop.org/article/10.1088/0957-4484/25/44/445501#metrics
Deposited by: Memoria Investigacion
Deposited on: 22 Dec 2015 18:26
Last Modified: 12 Jun 2019 08:09
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