Title
Analysis of Surface Passivation and Laser Firing on Thin-Film Silicon Solar Cells Via Light-Beam Induced Current
Date Issued
01 September 2020
Access level
metadata only access
Resource Type
journal article
Author(s)
Garud S.
Bokalic M.
Trinh C.T.
Amkreutz D.
Topic M.
Institute for Silicon Photovoltaics
Publisher(s)
IEEE Electron Devices Society
Abstract
Liquid phase crystallized silicon solar cells on glass have recently demonstrated 15.1% efficiency using a heterojunction interdigitated back contact cell architecture and an absorber thickness of 14 μm. One of the key enabling developments was a new method to first passivate electron contact fingers with a-Si:H(i) and then locally laser fire them to maintain a low contact resistance. In this work, high resolution, light-beam induced current measurements (LBIC) were used to analyze this approach. Charge collection was observed to have increased from 0.13 mAcm-2 to 0.9 mAcm-2 under the electron contact which is a sevenfold increase. Using 520, 642, 932, and 1067 nm wavelengths of incident light, external quantum efficiency was mapped in regions including grain boundaries, dislocation defects, shunts, defect-free regions, and laser fired spots. Reduction of charge collection in the laser fired spots was limited to diameters of 50-20 μm, depending on whether electrical recombination or optical losses dominated. Effective minority carrier diffusion length under the majority carrier contacts was obtained by fitting of LBIC measurements. It was observed to have improved from 20.5 μm to 22.7-40.4 μm and up to 89.0 μm in the best case. Based on this, wider contact fingers and improved surface passivation at the electron contact is encouraged in the near future to achieve efficiencies ≥16%.
Start page
1246
End page
1253
Volume
10
Issue
5
Number
9127969
Language
English
OCDE Knowledge area
Ingeniería de materiales
Scopus EID
2-s2.0-85087505832
Source
IEEE Journal of Photovoltaics
ISSN of the container
21563381
Sponsor(s)
Manuscript received March 7, 2020; revised May 7, 2020; accepted June 5, 2020. Date of publication June 29, 2020; date of current version August 20, 2020. This work was supported in part by the European Regional Development and the State Government of North Rhine-Westphalia in the Framework of the Up-LLPC Project under Grant EFRE-0800580 and Grant EU-1-2-037C and in part by the German Academic Exchange Service (DAAD) and Slovenian Research Agency (ARRS) for the bilateral project BI-DE/17-19/004. The work of Matevž Bokalicˇ and Marko Topicˇ was supported by the Slovenian Research Agency under program P2-0197. (Corresponding author: Siddhartha Garud.) Siddhartha Garud, Cham thi Trinh, and Daniel Amkreutz are with the Institute for Silicon Photovoltaics, Helmholtz-Zentrum Berlin für Materialien und En-ergie GmbH, 12489 Berlin, Germany (e-mail: garud.siddhartha@gmail.com; cham.trinh@helmholtz-berlin.de; daniel.amkreutz@helmholtz-berlin.de). European Regional Development Fund - EFRE-0800580, EU-1-2-037C - FEDER
Sources of information: Directorio de Producción Científica Scopus