The Role of N-Doped Multiwall Carbon Nanotubes in Achieving Highly Efficient Polymer Bulk Heterojunction Solar Cells

Abstract

This paper reports an improved solar cell performance of 8.6% by incorporation of N-doped multiwall carbon nanotubes (N-MCNTs) into BHJ solar cells composed of PTB7 and PC71BM. It was demonstrated for the first time that incorporation of N-MCNTs leads to not only increased nanocrystallite sizes but also smaller phase-separated domain sizes of both PTB7 copolymers and PC71BM from X-ray scattering study. The results show that N-MCNTs could serve as both exciton dissociation centers and charge transfer channels. The enhanced charge dissociation probabilities and effective charge carrier lifetime in the active layer material offer evidence to support the conclusion that N-MCNTs facilitated charge separation and transport.

Towards High Performance Organic Photovoltaic Cells: A Review of Recent Development in Organic Photovoltaics

“…Moreover, adding 1:250 of 2,3,5,6-tetrafuloro-7,7,8,8-tetracyanoquinodimethane (F4-TCNQ) on the active layers of PCDTBT:PC 70 BM could improve the PCE from 6.41% to 7.94%, which was mainly ascribed to the enhancement of J SC from 11.0 to 14.0 mA/cm 2 [172]. Furthermore, 1.5% N-doped carbon nanotube was found to be an effective additive in PTB7:PCBM BHJ, resulting in an enhanced PCE from 7.3% to 8.6% [173]. In addition, 2,3-bis(5-bromothiophene-2-yl)acrylonitrile (DTDBAL) was synthesized by Chen et al to improve the charge transport and exciton dissociation in the P3HT/PCBM system, and a 36% increase in PCE has been observed [174].…”

Fullerene derivatives as nano-additives in polymer composites

“…61 Improved charge transport and charge collection efficiency, as well as more effective light absorption in the blended solar cell with additives are the main factors responsible for the PCE enhancement. 62 Formic acid (FA) was also suggested 63 as a novel additive to improve the performance of a PTB7:PC 70 BM solar cell and to increase the short circuit current J SC . A significant increase in J SC from 14.57 to 24.11 mA cm 72 upon the addition of FA was attributed to enhanced charge carrier mobility, enhanced light absorption and more effective exciton generation.…”

The role of photonics in energy

“…[64][65][66][67] The chemical nature of the electron donor polymers has evolved from simple structures, such as PPV and poly(3-hexylthiophene) (P3HT), to more complex copolymers specially designed to have both electron donor and acceptor groups in their structures in order to reduce their bandgap. One example is the newly synthesized narrow-bandgap semiconducting polymer poly…”