Accelerated reliability tests of n+ and p+ poly-Si passivated contacts

Abstract

We report on the stability of encapsulated, low-pressure chemical vapor-deposited phosphorus ( n + poly-Si) doped and boron ( p + poly-Si) doped poly-Si/SiO x passivated contacts by exposing the samples to three different accelerated tests: damp heat test, thermal cycling and ultraviolet exposure, adhering closely to the IEC 61215 standard. Outdoor testing was also performed by exposing the samples in the outdoor testing field at the National Renewable Energy Laboratory, and preliminary data accumulated for 1000 h from February to April of 2021 is reported. We studied non-metallized, thermally-metallized, and screen-printed n + and p + poly-Si by monitoring the effective minority carrier lifetime at the implied maximum power point using a Sinton lifetime tester, and recorded photoluminescence images before and after the exposure. The samples were found to be stable under all test conditions, which is encouraging for incorporation of these contacts in next-generation industrial silicon solar cells. • Three accelerated tests performed on encapsulated LPCVD n + and p + poly-Si/SiO x , adhering closely to IEC 61215 standard. • Samples include non-metallized, thermally metallized, and screen-printed n + and p + poly-Si/SiO x . • Effective minority carrier lifetime and PL images of the sample monitored. • All samples found to be stable after the exposure to accelerated and outdoor tests.