| Summary: | 碩士 === 國立中央大學 === 物理研究所 === 95 === The main goal of the experiment is to grow hydrogenated
amorphous silicon i-a-Si:H, p-a-Si:H and n-a-Si:H thin films of better
single condition chosen to fabricate devices on glass by PECVD (plasma
enhanced chemical vapor deposition) for analyzing electrical, optical,
structural and morphological characteristics. Then, the two same pin solar
cells are made of better condition in order to study electrical
characteristics, efficiency and repeated characterization of the
experiment.
For i layer thin film, its resistivity is in the normal value compared
with the reference value ; the resistivities of the other p layer and n layer
thin films are both smaller by two orders of magnitude than that of the
reference values. In other words, the carrier concentrations of p layer and n layer thin films are in the normal values. The experimental values of player are compared with another values of the reference, and its τe and Le
are with better characteristics ; the experimental values of n layer are
compared with another values of the reference, and its τh and Lh are with
normal characteristics.
To check the three samples from optical band gap, their values are
all in the range from 1.5 to 2.0 eV. Therefore, it can indirectly show the
existence of the amorphous structure. From the Raman spectrum curves,
its peak value is at 477 cm-1 and which shows that the structure for player is the amorphous silicon. On the other hand, the peak value at 477cm-1 depicts the existence of the amorphous silicon structure for n layer.
Moreover, two peaks at 504 and 513 cm-1 proves the existence of the
nanocrystal silicon in the amorphous silicon structure for n layer.
For the amorphous silicon thin films made in the electrical and
optical devices, their surface roughness is also an important affection
where they are under 5 nm for the three samples with less for the surface
roughness. Furthermore, the films are checked for the uniforms and
roughness by SEM.
Considering Pmax, Jsc, Voc and η in the same conditions and
environments from the two same devices, their physical values are the
same experimentally, and it proves the high repeated characteristic. As a
result, the associated characteristic of the similar qualities for the growth
of the thin films and devices can be believed.
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