Fig. 1. (a) Schematic showing the structure of our CNT-based millimetric photodetector. (b) Optical image of a photodetector constructed using large-diameter small-bundle SWCNT ?lms, showing that it is transparent and bendable. (c) Typical SEM images of large-diameter small-bundle SWCNT films. (d) Typical TEM images of large-diameter small-bundle SWCNT films. (e) G- and D-bands Raman spectra of the large-diameter small-bundle SWCNT films excited with a 633 nm wavelength laser. (f) Typical TEM image of common large-bundle SWCNT network.

Fig. 2. (a) I-V characteristics of the device. The inset shows the dependence of photocurrent on bias voltage. (b) Photoresponse curves of the device upon multiple cycles. (c) Comparative photoresponse curves of the devices before and after exposing in air for 6 months. (d) Photoresponse curves of the device illuminated by lasers with different wavelengths and roughly the same power. The bias voltage was 0.2 V.

Fig. 3. (a) Dependence of photocurrent |ΔI| on the absorbed light power. (b) Photoresponse curves of the devices with different SWCNT film transmittances. (c) Dependence of responsivity of the devices on the transmittance of SWCNT films. (d) Photoresponse curves of the device with different width of suspended SWCNT film.

Fig. 4. Photoresponse curves of the device based on small-bundle SWCNTs and large-bundle SWCNTs.