Enhanced performance of inverted organic photovoltaic cells using CNTs-TiO(X) nanocomposites as electron injection layer.
In this study, we fabricated inverted organic photovoltaic cells with the structure ITO/carbon nanotubes (CNTs)-TiO(X)/P3HT:PCBM/MoO₃/Al by spin casting CNTs-TiO(X) nanocomposite (CNTs-TiO(X)) as the electron injection layer onto ITO/glass substrates. The power conversion efficiency (PCE) of the 0.1 wt% single-walled nanotubes (SWNTs)-TiO(X) nanocomposite device was almost doubled compared with the TiO(X) device, but with increasing concentration of the incorporated SWNTs in the TiO(X) film, the performance of the devices appeared to decrease rapidly. Devices with multi-walled NTs in the TiO(X) film have a similar trend. This phenomenon mainly depends on the inherent physical and chemical characteristics of CNTs such as their high surface area, their electron-accepting properties and their excellent carrier mobility. However, with increasing concentration of CNTs, CNTs-TiO(X) current leakage pathways emerged and also a recombination of charges at the interfaces. In addition, there was a significant discovery. The incorporated CNTs were highly conducive to enhancing the degree of crystallinity and the ordered arrangement of the P3HT in the active layers, due to the intermolecular π-π stacking interactions between CNTs and P3HT.
CAS Key Lab for Biomedical Effects of Nanomaterials and Nanosafety, Institute of High Energy Physics, Chinese Academy of Sciences, National Center for Nanoscience and Technology of China, Beijing 100049, People's Republic of China.
Hong
H
Zhang
Meifeng
M
Xu
Rongli
R
Cui
Xihong
X
Guo
Shangyuan
S
Yang
Liangsheng
L
Liao
Quanjie
Q
Jia
Yu
Y
Chen
Jinquan
J
Dong
Baoyun
B
Sun