Detailed balance analysis and enhancement of open-circuit voltage in single-nanowire solar cells.
We present a detailed balance analysis of current density-voltage modeling of a single-nanowire solar cell. Our analysis takes into account intrinsic material nonidealities in order to determine the theoretical efficiency limit of the single-nanowire solar cell. The analysis only requires the nanowire's absorption cross-section over all angles, which can be readily calculated analytically. We show that the behavior of both the current and voltage is due to coherent effects that arise from resonances of the nanowire. In addition, we elucidate the physics of open-circuit voltage enhancement over bulk cells in nanowires, by showing that the enhancement is related to the removal of resonances in the immediate spectral vicinity above the bandgap.
Department of Electrical Engineering, Stanford University , Stanford, California 94305, United States.
Sunil
S
Sandhu
Zongfu
Z
Yu
Shanhui
S
Fan