Analysis of Series Resistance Losses in a-Si:H/c-Si Heterojunction Solar Cells

Author

Gogolin, Ralf ; Turcu, Mircea ; Ferre, Rafel ; Clemens, Joachim ; Harder, Nils-Peter ; Brendel, Rolf ; Schmidt, J.

Author_Institution

Inst. for Solar Energy Res. Hamelin, Emmerthal, Germany

Volume

4

Issue

5

fYear

2014

fDate

Sept. 2014

Firstpage

1169

Lastpage

1176

Abstract

We present an experimental method to quantify the series resistance R_a-Si/ITO through the a-Si:H layers and the a-Si:H/ITO interface on test structures. In order to optimize R_a-Si/ITO, we apply different a-Si:H and ITO deposition parameters. We find the best value for R_(p)-a-Si/ITO of 0.42 Ω·cm² for an ITO double layer with a 10-nm-thin starting layer that provides good contact resistance and an additional 90-nm top layer that provides good conductivity. For R_(n)-a-Si/ITO, we reach values below 0.1 Ω·cm². We present an analysis of the series resistance and shading losses of our 100-cm² bifacial screen-printed a-Si:H/cSi heterojunction solar cells, which show an open-circuit voltage of V_oc = 733 mV, demonstrating the excellent level of interface passivation. The efficiency of 20.2% is limited by a low short-circuit current density of 37.1 mA/cm² and fill factor of 76%.

Keywords

amorphous semiconductors; contact resistance; current density; electrical conductivity; elemental semiconductors; hydrogen; indium compounds; passivation; semiconductor heterojunctions; short-circuit currents; silicon; solar cells; tin compounds; ITO deposition parameters; Si:H-Si-ITO; conductivity; fill factor; interface passivation; open-circuit voltage; resistance; screen-printed heterojunction solar cells; series resistance losses; short-circuit current density; Conductivity; Contact resistance; Heterojunctions; Hydrogen; Indium tin oxide; Photovoltaic cells; Resistance; Amorphous silicon; series resistance; silicon heterojunction solar cells;

fLanguage

English

Journal_Title

Photovoltaics, IEEE Journal of

Publisher

ieee

ISSN

2156-3381

Type

jour

DOI

10.1109/JPHOTOV.2014.2328575

Filename

6838961