TY - JOUR

T1 - Junction Resistivity of Carrier-Selective Polysilicon on Oxide Junctions and Its Impact on Solar Cell Performance

AU - Rienacker, Michael

AU - Bossmeyer, Marcel

AU - Merkle, Agnes

AU - Romer, Udo

AU - Haase, Felix

AU - Krugener, Jan

AU - Brendel, Rolf

AU - Peibst, Robby

N1 - Funding Information: This work was performed in the framework of HERCULES. The project HERCULES has received funding from the Eu- ropean Union’s Seventh Program for research, technological development and demonstration under grant agreement no. 608498. The authors would like to thank M. Pickrell from Sun Chemical Ltd. for providing the hotmelt wax. They appreciate H. Fischer, T. Friedrich, F. Heinemeyer, S. Kirstein, H. Kohlenberg, A. Raugewitz, D. Sylla, and N. Wehmeier from the Institute for Solar Energy Research Hamelin for the processing of TLM test structures and solar cells. They would also like to thank B. Wolpensinger and S. Sch¤afer for SEM investigations, F. Kiefer and R. Winter for ECV measurements, and M. Wolf for fruitful discussions concerning LOANA measurement. Special thanks is due to G. Glowatzki and B. Koch from the Institute of Elec- tronic Materials and Devices, Leibniz Universität Hannover, for helping with ion implantation, photolithography, and reactive ion etching, as well as the Laboratory of Nano and Quantum Engineering, Leibniz University of Hanover, for support.

PY - 2017/1

Y1 - 2017/1

N2 - We investigate the junction resistivity of high quality carrier selective polysilicon on oxide (POLO) junctions with the transfer length method. We demonstrate n + POLO junctions with a saturation current density J c, poly of 6.2 fA/cm 2 and junction resistivity p c of 0.6 mΩcm 2 , counterdoped n + POLO junctions with 2.7 fA/cm 2 and 1.3 mΩcm 2 , and p + POLO junctions with 6.7 fA/cm 2 and 0.2 mΩcm 2 . Such low junction resistivities and saturation current densities correspond to excellent selectivities of up to 16.2 and imply a contribution of only a few mΩcm 2 to the total series resistance of the cell, enabling an efficiency potential larger than 26 %, which was estimated by numerical device simulations. We demonstrate experimentally a back-junction back contacted solar cell with p-type and n-type POLO junctions with an efficiency of 23.9 %. This efficiency is the largest reported so far for cells with polysilicon junctions for both contacts and it is limited by the passivation of undoped regions.

AB - We investigate the junction resistivity of high quality carrier selective polysilicon on oxide (POLO) junctions with the transfer length method. We demonstrate n + POLO junctions with a saturation current density J c, poly of 6.2 fA/cm 2 and junction resistivity p c of 0.6 mΩcm 2 , counterdoped n + POLO junctions with 2.7 fA/cm 2 and 1.3 mΩcm 2 , and p + POLO junctions with 6.7 fA/cm 2 and 0.2 mΩcm 2 . Such low junction resistivities and saturation current densities correspond to excellent selectivities of up to 16.2 and imply a contribution of only a few mΩcm 2 to the total series resistance of the cell, enabling an efficiency potential larger than 26 %, which was estimated by numerical device simulations. We demonstrate experimentally a back-junction back contacted solar cell with p-type and n-type POLO junctions with an efficiency of 23.9 %. This efficiency is the largest reported so far for cells with polysilicon junctions for both contacts and it is limited by the passivation of undoped regions.

KW - Back-junction back-contact (BJBC) cells

KW - contact resistivity

KW - polysilicon

KW - polysilicon on oxide (POLO) junctions

KW - recombination

KW - selective contacts

KW - selectivity

UR - http://www.scopus.com/inward/record.url?scp=84996605322&partnerID=8YFLogxK

U2 - 10.1109/PVSC.2017.8366491

DO - 10.1109/PVSC.2017.8366491

M3 - Article

AN - SCOPUS:84996605322

VL - 7

SP - 11

EP - 18

JO - IEEE Journal of Photovoltaics

JF - IEEE Journal of Photovoltaics

SN - 2156-3381

IS - 1

M1 - 7747536

ER -