Air-stable high-efficiency solar cells with dry-transferred single-walled carbon nanotube films†
* Corresponding authors
a
Department of Mechanical Engineering, The University of Tokyo, Bunkyo-ku, Tokyo 113-8656, Japan
E-mail:
maruyama@photon.t.u-tokyo.ac.jp
Fax: +81-3-5800-6983
Tel: +81-3-5841-6421
b Canatu Ltd, Konalankuja 5, FI-00390 Helsinki, Finland
c Nanosystem Research Institute, National Institute of Advanced Industrial Science and Technology, Tsukuba 305-8562, Japan
d Department of Applied Physics, Aalto University School of Science, Aalto FI-00076, Finland
e Skolkovo Institute of Science and Technology, 100 Novaya st., Skolkovo, Moscow Region, Russia 143025
Abstract
By using the excellent optical and electrical properties of pristine SWNTs with long bundle lengths, we present single-walled carbon nanotube–silicon (SWNT/Si) solar cells of 11% power conversion efficiency (PCE), prepared without doping. The PCEs of the fabricated solar cells even increased slightly after 10 months of exposure to ambient conditions, without any external protection. The open-circuit voltage of the SWNT/Si solar cells under low light intensities, down to 10 mW cm−2, demonstrated the characteristics of the ideal p–n junction model. The mechanism was discussed, taking into account the effect of varying the interfacial oxide layer thickness between the SWNTs and Si on the solar cell’s performance. The high efficiency and stability demonstrated in this study make SWNT/Si solar cells one of practical choices for next generation energy system.