title: Light-harvesting using high density p-type single wall carbon nanotube/n-type silicon heterojunctions.
abstract: Photovoltaic conversion was achieved from high-density p-n heterojunctions between single-wall carbon nanotubes (SWNTs) and n-type crystalline silicon produced with a simple airbrushing technique. The semitransparent SWNT network coating on n-type silicon substrate forms p-n heterojunctions and exhibits rectifying behavior. Under illumination the numerous heterojunctions formed between substrate generate electron-hole pairs, which are then split and transported through SWNTs (holes) and n-Si (electrons), respectively. The nanotubes serve as both photogeneration sites and a charge carriers collecting and transport layer. Chemical modification by thionyl chloride of the SWNT coating films was found to significantly increase the conversion efficiency by more than 50% through adjusting the Fermi level and increasing the carrier concentration and mobility. Initial tests have shown a power conversion efficiency of above 4%, proving that SOCl(2) treated-SWNT/n-Si configuration is suitable for light-harvesting at relatively low cost.
authors.affiliation: Nanotechnology Center, University of Arkansas at Little Rock, AR 72204, USA. zxli3@ualr.edu
authors.forename: Zhongrui
authors.initials: Z
authors.lastname: Li
authors.forename: Vasyl P
authors.initials: VP
authors.lastname: Kunets
authors.forename: Viney
authors.initials: V
authors.lastname: Saini
authors.forename: Yang
authors.initials: Y
authors.lastname: Xu
authors.forename: Enkeleda
authors.initials: E
authors.lastname: Dervishi
authors.forename: Gregory J
authors.initials: GJ
authors.lastname: Salamo
authors.forename: Alexandru R
authors.initials: AR
authors.lastname: Biris
authors.forename: Alexandru S
authors.initials: AS
authors.lastname: Biris