Abstract :
In the present study, the effect of in situ layer-by-layer oxygen plasma treatment (OPT) on optical, nano-mechanical and electrical
properties of layer-by-layer diamond-like carbon (DLC) thin films was explored. In situ layer-by-layer OPT on layer-by-layer DLC films
led to drastic variation of optical band gap from 1.25 eV to 2.6 eV and hardness from 16.1 GPa to 25.3 GPa. Wide band gap and the
band gap feasibility over wide range may lead to its realization as p-type window layer in p–i–n solar cells and variable band gap layers
in tandem solar cells. Simulations of a-Si:H based p–i–n solar cells was also carried out by considering OPT–DLC films as p-type window
layers that yielded maximum efficiency of 8.9%. In addition, due to high hardness and other excellent nano-mechanical properties, these
OPT–DLC films can be treated as hard, protective and encapsulate layers on solar cells particularly in n–i–p configuration. It is important
to mention that OPT–DLC film as p-layer can minimize the use of additional hard, protective and encapsulate layer.
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