Single carbon nanotube photovoltaic device

Abstract

Here we present photocurrent measurements on a single suspended carbon nanotube p-n junction. The p-n junction was induced by electrostatic doping by local gates, and the E11 and E22 resonances in the nanotube could be probed using photocurrent spectroscopy. Current-voltage characteristics were recorded, revealing an enhanced optoelectronic response on resonance. The internal power conversion efficiency for the nanotube diode was extracted on and off resonance with the E11 and E22, and a large internal power conversion efficiency was observed. An internal efficiency of up to 23% is reported for the E11, showing the potential of carbon nanotubes to be used as the active element in photovoltaic devices. Finally, a photovoltaic device is proposed which exploits this enhanced efficiency. V C 2013 AIP Publishing LLC.

On a rapidly converging iterative algorithm for diode parameter extraction from a singleIVcurve

“…This is an active area of research, in which periodically the state of the art is summarized in review articles such as [6] for the Schottky diode, [8] for the solar cells and [5] for the diode and solar cells, just to cite a few of them. Moreover, the method of I-V characteristic is also used in different research areas, such as, for example, [26]. As can be seen by reading these papers, the methods are several and in general the number of fitting parameters can be higher than four and moreover the relatioship between the parameters and the underlying physical processes can be difficult to establish.…”

Photocurrent Spectroscopy of (n, m) Sorted Solution-Processed Single-Walled Carbon Nanotubes

“…In other words the photocurrent in s-SWCNTs arises from an electric field (built-in or applied), and the photocurrent in m-SWCNTs is mediated by a difference in Seebeck coefficients. In performing their study Barkelid et al 20,21 addressed a problem in the literature, namely, seemingly conflicting results with some reports stating the photocurrent to be photothermoelectric 23À26 in origin while others showed a photovoltaic behavior. 16,17,22 Reflecting on the device design of many groups reporting photothermoelectric origins, either unsorted metallic CNTs 24 or a film of CNTs was used.…”

“…Techniques such as dielectrophoretic deposition from solution , or chemical vapor deposition (CVD) growth of SWCNTs between metalized source and drain contacts in CNT field-effect transistors are becoming standard. In this architecture photogenerated electrons and holes are typically separated by either an externally applied gate bias or internal fields at the SWCNT–metal Schottky barrier. ,,, Photocurrent generation has therefore been studied in both substrate-supported ,− and unsupported − CNTs. However, unlike in the case of the SWCNT films discussed previously, a laser is typically used to address the CNTs due to the high power density required to measure photocurrent from only a few CNTs.…”

“…Most recently, Barkelid et al . , used a similar split gate design and provided a comparison of the photocurrent generated in semiconducting and metallic carbon nanotubes. In their work they suggest that the photocurrent generated from semiconducting nanotubes had photovoltaic origins, whereas in the case of metallic nanotubes it was photothermoelectric.…”

“…In other words the photocurrent in s-SWCNTs arises from an electric field (built-in or applied), and the photocurrent in m-SWCNTs is mediated by a difference in Seebeck coefficients. In performing their study Barkelid et al . , addressed a problem in the literature, namely, seemingly conflicting results with some reports stating the photocurrent to be photothermoelectric − in origin while others showed a photovoltaic behavior. ,, Reflecting on the device design of many groups reporting photothermoelectric origins, either unsorted metallic CNTs or a film of CNTs was used. , Hence discrimination between these two effects was understandably difficult. However, in the work of Amer et al ., who exclusively worked on split gate devices from metallic CNTs, it is important to note that the photocurrent signal was clearly seen to originate from the center of the nanotube (position of split gates), which would suggest that the photocurrent originated from the p–n junction rather than the contacts.…”