High Efficiency Graphene Solar Cells by Chemical Doping

TL;DR

This paper reports a significant improvement in graphene/n-Si Schottky junction solar cells achieved through chemical doping, resulting in a high power conversion efficiency of 8.6%, surpassing previous records.

Contribution

The study introduces a doping method using bis(trifluoromethanesulfonyl)amide to enhance graphene's electrical properties, leading to substantially higher solar cell efficiency.

Findings

Doping increases graphene carrier density and built-in potential.

Efficiency improved by a factor of 4.5 over undoped devices.

Achieved a PCE of 8.6% under standard illumination.

Abstract

We demonstrate single layer graphene/n-Si Schottky junction solar cells that under AM1.5 illumination exhibit a power conversion efficiency (PCE) of 8.6%. This performance, achieved by doping the graphene with bis(trifluoromethanesulfonyl)amide, exceeds the native(undoped) device performance by a factor of 4.5 and the best previously reported PCE in similar devices by a factor of nearly 6. Current-voltage, capacitance-voltage and external quantum efficiency measurements show the enhancement to be due to the doping induced shift in the graphene chemical potential which increases the graphene carrier density (decreasing the cell series resistance) and increases the built-in potential.