RESPONSE OF ASYMMETRIC DEVICES BASED ON CARBON NANOTUBES ON
SUB-TERAHERTZ RADIATION
A. I. Kardakova 1, G. E. Fedorov 1,2, I. A.
Gayduchenko 1,2, I. A. Charayev 1, B. M. Voronov
1, M. I. Finkel 1, G. N. Goltsman 1
1
Moscow State Pedagogical University, Moscow
2
National Research Centre “Kurchatov Institute”, Moscow
The paper is received on October 28, 2014
Abstract. In
this paper we report on the response of the asymmetric devices based on carbon
nanotubes (CNT) on the sub-terahertz radiation. Sensing element of the devices
is a dense CNTs network formed by chemical vapor deposition near the catalytic
island. Asymmetry of the investigated devices is inhomogeneous morphology of
the CNT film which contacted with the metal electrodes. One of the electrodes contacts
the part of the CNT-nets which is on the catalytic island where most of the
nanotubes are suspended. The second contact connects to the other part of the
CNT-network in which the nanotubes are in direct contact with the substrate. This
results in the device's asymmetry associated with different thermal contact of the
CNT film with the substrate. Under the radiation with a frequency of 140 GHz
the DC voltage is observed at zero current bias. Analysis of the dependence of
the response on the incident radiation power and the gate voltage in a wide
temperature range suggests that the observed effect has a dual nature: thermal
and photovoltaic. Volt-watt sensitivity of the device at room temperature
exceeds the values which were earlier reported for detectors based on CNTs for
submillimeter and THz ranges.
Key words: carbon
nanotubes, THz detectors.