Electrical Properties of Nanocrystalline n-SnO2 to Single Crystal p-Si Interfaces under Gas Adsorption Conditions

Autor: Alexander Gaskov, Ludmila I. Ryabova, Marina Rumyantseva, Roman B. Vasiliev, B. A. Akimov
Rok vydání: 2001
Předmět:
Zdroj: physica status solidi (a). 188:1093-1104
ISSN: 1521-396X
0031-8965
DOI: 10.1002/1521-396x(200112)188:3<1093::aid-pssa1093>3.0.co;2-x
Popis: We present a study of heterostructures based on thin n-SnO 2 layers prepared by means of an aerosol pyrolysis on a single crystalline p-Si substrate. SnO 2 films are composed of 6-8 nm grains segregated into agglomerates of about 0.1 μm providing a porous structure of the film. Current-voltage (I-V) characteristics are taken in the temperature interval 180-300 K. Capacitance-voltage (C-V) curves are obtained at frequencies of the reference signal varied within 0.5-20 kHz at 300 K. Electrical properties of the structures were examined in air and in gas mixtures N 2 + 0.1% NO 2 and N 2 + 1% C 2 H 5 OH. A pronounced non-linearity of the I-V curves is explained in terms of the Schottky equation with high ideality factors β 7 - 11. The gas sensitivity S depends on the kind of adsorbed gas molecule due to the Schottky barrier variation together with the interface states density change. The SnO 2 doping with Ni induces an increase of S by an order of magnitude.
Databáze: OpenAIRE