High performance multiwall carbon nanotube bolometers

High infrared bolometric photoresponse has been observed in multiwall carbon nanotube (MWCNT) films at room temperature. The observed detectivity D* in exceeding 3.3 x 106 cm Hz(1/2)/W on MWCNT film bolometers is a factor of 7 higher than that obtained on the single-wall CNT (SWCNT) counterparts. The response time of about 1-2 ms on MWCNT bolometers is more than an order of magnitude shorter than that of SWCNT bolometers. The observed high performance may be attributed to the naturally suspended inner-shell structure in a MWCNT, which enhances photon absorption and restricts bolometer external thermal link to environment. (C) 2010 American Institute of Physics. [doi:10.1063/1.3492633]