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Abstract
This thesis is divided into three main chapters, covering Flash Lamp Annealing (FLA)
experiments in Chapter 1, FLA thermal and structural simulations in Chapter 2, and
Photoluminescence (PL) Imaging in Chapter 3.
The first and second chapters aim to gauge the feasibility of replacing the existing belt
furnace Rapid Thermal Process (RTP) with FLA for Silicon (Si) films on a glass
substrate that have been crystallised by Solid Phase Crystallisation (SPC). The
experimental work gives us insight into the maximum stress that the film can handle
during the FLA process, as well as giving us a baseline for parameters to investigate in
any future experiments. It is found that FLA with 3ms pulses and 20ms pulses are not
suitable replacements for the current RTP setup because significant damage to the film
is observed at lower pulse energy densities than that required to achieve an adequate
level of annealing. The modelling in chapter 2 predicts that the magnitude of the stress
will increase with increasing pulse duration, making successful annealing at longer
pulse durations unlikely.
Equipment capable of producing pulse durations above 80 milliseconds, and capable of
heating the Si film to temperatures between 1350°C to 1400°C does not currently exist.
For this reason these pulse durations have not been investigated, but a basic design
guide on how longer pulse durations could be produced is provided.
The third chapter concentrates on PL Imaging of thin film Silicon Solar cells on glass.
PL Imaging allows a noncontact method of characterising the quality of the Silicon film
at various stages of the production process. Through PL Imaging, it was discovered that
there is a large variation in material quality from sample to sample, as well as within the
same sample. It is also found that the PL signal is wavelength dependent, and through
modelling of cell parameters in PC1D, we can use this wavelength dependence to infer
a minority carrier lifetime on low quality Si material.