Abstracts Book - IMRC 2018

• SC4-O023
STABILITY IMPROVEMENT ON POLYMORPHOUS SILICON THIN
FILMS SOLAR CELLS
Leon Hamui Balas 1
1 Universidad Anáhuac México Norte, Ingenieria, Mexico.
This work describes the improvement of the pm-Si:H solar cell stability by terms
of thermal annealing. The solar structures were deposited by a conventional
plasma enhanced chemical vapor deposition (PECVD) using as precursor gases
Hydrogen (H2) and silane (SiH4). PIN and NIP configurations were obtained and
deposited on SnO2 in order to be compared and characterized. The pm-Si:H is a
material composed by silicon nanocrystals (around 2 - 6 nm) in an a-Si:H matrix.
Thermal annealing experiments were conducted with simultaneous hydrogen
exodiffusion measurements in order to aim better stability and cell performance
which in turns affects the physics of the device. The latter by the analysis of
structural and optical properties. The film structural and optical properties
varied slightly with the thermal annealing. There is a different diffusion process
depending on the film order. The crystalline fraction of these structures is
observed to be maintained almost constant. . A large amount of hydrogen is
concentrated on the surface of the PIN top film generating a change on the
microstructure. Hydrogen rearrangement on films and microstructure changes
were observed. The total hydrogen that effuses from PIN structure is lower than
for the NIP related to defects creation after induced hydrogen diffusion, break
of Si-H bonds and the generation of dangling bonds. Both structures present an
ohmic behavior on the dark-IV curve and an important photoelectric response.
These could give significant evidence for a more stable device and enhanced
functional performance of this type of structure.
Acknowledgment:
We acknowledge the financial support from Anahuac México University, Project
number INNDIAHABL170215171.
Keywords: silicon, Diffusion, stability
Presenting authors email: famhamui@yahoo.com