Phosphorus-doped Amorphous Silicon Nitride Films Applied to Crystalline Silicon Solar Cells
Tutor/a - Director/a
Schubert, Marcus
Estudiante
Feinäugle, Matthias
Tipo de documento
Projecte Final de Màster Oficial
Fecha
2009
rights
Acceso abierto
Editorial
Universitat Politècnica de Catalunya
UPCommons
Resumen
The Photovoltaics Group at the Universitat Politècnica de Catalunya is investigating
silicon carbide (SiC) for the electronic passivation of the surface
of crystalline silicon solar cells. The doping of SiC passivation layers with
phosphorus resulted in a clear improvement of the minority carrier lifetime
compared to undoped SiC films applied on p-type doped substrate wafers. In
a further approach, the passivation layers simultaneously served as a doping
source in order to create an emitter in the underlying p-type doped silicon
substrate.
The aim of this Master Thesis is to establish a process for growing silicon
nitride (SiN) on p-type doped crystalline silicon substrates from Plasma Enhanced
Chemical Vapor Deposition (PECVD). Photoconductance measurements
on the samples analyse the passivating behaviour of the SiN films.
The passivation layers are doped by adding phosphine to the process gas,
and further measurements investigate the effect of doping on the carrier lifetime.
Furthermore, a thermal treatment initiates the diffusion of phosphorus
in order to create an emitter in the substrate underneath. Sheet resistance
(Rsq) and the lower limit of the emitter saturation current density (J0e) deduced
from lifetime measurements, characterise the quality of the emitters.
Eventually, a cell prototype finishes this work integrating both concepts of
using SiN as a passivation layer, and of diffusing an emitter from the very
same SiN layer.
Profesorado participante
- Schubert, Marcus