Itkis Mikhail E, Borondics Ferenc, Yu Aiping, Haddon Robert C
Center for Nanoscale Science and Engineering, Departments of Chemistry and Chemical and Environmental Engineering, University of California, Riverside, CA 92521-0403, USA.
Science. 2006 Apr 21;312(5772):413-6. doi: 10.1126/science.1125695.
The photoresponse in the electrical conductivity of a single-walled carbon nanotube (SWNT) film is dramatically enhanced when the nanotube film is suspended in vacuum. We show here that the change in conductivity is bolometric (caused by heating of the SWNT network). Electron-phonon interactions lead to ultrafast relaxation of the photoexcited carriers, and the energy of the incident infrared (IR) radiation is efficiently transferred to the crystal lattice. It is not the presence of photoexcited holes and electrons, but a rise in temperature, that results in a change in resistance; thus, photoconductivity experiments cannot be used to support the band picture over the exciton model of excited states in carbon nanotubes. The photoresponse of suspended SWNT films is sufficiently high that they may function as the sensitive element of an IR bolometric detector.
当单壁碳纳米管（SWNT）薄膜悬浮在真空中时，其电导率的光响应会显著增强。我们在此表明，电导率的变化是热辐射计式的（由SWNT网络的加热引起）。电子 - 声子相互作用导致光激发载流子的超快弛豫，并且入射红外（IR）辐射的能量被有效地转移到晶格中。导致电阻变化的不是光激发的空穴和电子的存在，而是温度的升高；因此，光电导实验不能用于支持碳纳米管激发态的能带图像而非激子模型。悬浮的SWNT薄膜的光响应足够高，以至于它们可以用作红外热辐射计探测器的敏感元件。
