Effect of Hysteresis on Measurements of Thin-Film Cell Performance

Authors

David S. Albin, National Renewable Energy LaboratoryFollow
Joseph A. del Cueto, National Renewable Energy Laboratory

Document Type

Conference Proceeding

Publication Date

3-2011

Publication Title

Reliability of Photovoltaic Cells, Modules, Components, and Systems III: SPIE Conference

Publisher

National Renewable Energy Laboratory

Publisher Location

Golden, CO

First page number:

1

Last page number:

9

Abstract

Transient or hysteresis effects in polycrystalline thin film CdS/CdTe cells are a function of pre-measurement voltage bias and whether Cu is introduced as an intentional dopant during back contact fabrication. When Cu is added, the current-density (J) vs. voltage (V) measurements performed in a reverse-to-forward voltage direction will yield higher open-circuit voltage (V_oc), up to 10 mV, and smaller short-circuit current density (J_sc), by up to 2 mA/cm², relative to scanning voltage in a forward-to-reverse direction. The variation at the maximum power point, Pmax, is however small. The resulting variation in FF can be as large as 3%. When Cu is not added, hysteresis in both Voc and Jsc is negligible however P_max hysteresis is considerably greater. This behavior corroborates observed changes in depletion width, W_d, derived from capacitance (C) vs. voltage (V) scans. Measured values of Wd are always smaller in reverse-to-forward voltage scans, and conversely, larger in the forward-to-reverse voltage direction. Transient ion drift (TID) measurements performed on Cu-containing cells do not show ionic behavior suggesting that capacitance transients are more likely due to electronic capture-emission processes. J-V curve simulation using Pspice shows that increased transient capacitance during light-soak stress at 100 ºC correlates with increased space-charge recombination. Voltage-dependent collection however was not observed to increase with stress in these cells.

Controlled Subject

Cadmium telluride; Solar cells; Deep level transient spectroscopy; Photovoltaic cells; Photovoltaic cells--Testing; Reliability (Engineering); Solar energy; Thin films

Disciplines

Oil, Gas, and Energy | Power and Energy

File Format

pdf

File Size

505 KB

Language

English

Comments

Presented at the Reliability of Photovoltaic Cells, Modules, Components, and Systems III: SPIE Conference, August 3-5, 2010, San Diego, California.

Rights

IN COPYRIGHT. For more information about this rights statement, please visit http://rightsstatements.org/vocab/InC/1.0/

Repository Citation

Albin, D. S., del Cueto, J. A. (2011). Effect of Hysteresis on Measurements of Thin-Film Cell Performance. Reliability of Photovoltaic Cells, Modules, Components, and Systems III: SPIE Conference 1-9.
Available at: https://digitalscholarship.unlv.edu/renew_pubs/50