Light-harvesting using high density p-type single wall carbon nanotube/n-type silicon heterojunctions.
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.
Li
Zhongrui
Z
Nanotechnology Center, University of Arkansas at Little Rock, AR 72204, USA. zxli3@ualr.edu
Kunets
Vasyl P
VP
Saini
Viney
V
Xu
Yang
Y
Dervishi
Enkeleda
E
Salamo
Gregory J
GJ
Biris
Alexandru R
AR
Biris
Alexandru S
AS