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Title: Inserting a Low-Refractive-Index Dielectric Rear Reflector into PERC Cells: Challenges and Opportunities: Preprint

Conference ·
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  1. ASU
  2. International Solar Energy Research Center Konstanz
  3. National Renewable Energy Laboratory (NREL), Golden, CO (United States)

One of the simplest and most effective ways to reduce the operating temperature of photovoltaic systemsin the field is to reflect unusable, 'sub-bandgap' lightwith energies below the cell absorber's bandgap energy. In this work, low-refractive index SiO2nanoparticle films inserted between c-Si wafers and metal electrodes significantly increase the reflectance of sub-bandgap light in fabricated test structures. These films are then integrated intothestandard PERC fabrication sequence, revealing that thereflection benefits remains after some processing stepsbut are lost in certain conditions. The SiO2nanoparticle films are easily ablatedduring laser contact opening, but are undesirably etched during post-laser cleaning. After Al metallization, the fully fabricated devices show enhanced sub-bandgap reflection when annealed at moderate temperatures, but energy-dispersive x-ray spectroscopy showsthat high-temperature firing causes unwanted Al penetration into the SiO2nanoparticle film, compromising reflection.

Research Organization:
National Renewable Energy Lab. (NREL), Golden, CO (United States)
Sponsoring Organization:
USDOE Office of Energy Efficiency and Renewable Energy (EERE), Renewable Power Office. Solar Energy Technologies Office
DOE Contract Number:
AC36-08GO28308
OSTI ID:
1579631
Report Number(s):
NREL/CP-5K00-75157
Resource Relation:
Conference: Presented at the 46th IEEE Photovoltaic Specialists Conference (PVSC 46), 16-21 June 2019, Chicago, Illinois
Country of Publication:
United States
Language:
English