Daniel McCulley¹ Mitchell Senger¹ Ethan Minot¹

1, Oregon State University, Corvallis, Oregon, United States

Pristine, defect-free, suspended carbon nanotubes (CNTs) are an ideal system to study photocurrent generation in the limit of strong Coulomb interactions. Photon-to-electron conversion efficiencies exceeding 100% have already been shown in quantum dot solar cells, and carrier multiplication effects have been reported in CNT photodiodes. However, measurements of CNT photodiodes have so far yielded disappointing internal quantum efficiencies (< 70%). Our experiments utilize fully-suspended dual-gated carbon nanotubes with axial electric fields up to ~ 15 volts per micron. Building on our past results (Aspitarte, Nano Letters 2016), we use stronger electric fields to increase the exciton dissociation rate and unlock the possibility of harnessing carrier multiplication. We present our recent progress toward demonstrating internal quantum efficiencies greater than 100%.