The a-C:H/p-Si solar cell deposited by pulsed laser deposition

Hydrogenated amorphous carbon films (a-C:H) were deposited on p-type silicon as well as silica substrates by pulsed laser deposition technique using a mixture of graphite and camphor powders. The Fourier transform infrared spectroscopy measurement revealed the presence of hydrogen in the a-C:H films. The optical properties and structure of the a-C:H film were investigated by UV–visible and Raman scattering spectroscopy. The formation of a heterojunction between the a-C:H film and silicon substrate was confirmed by the current–voltage (I–V) measurement. Furthermore, the structure of a-C:H/p-Si showed photovoltaic characteristics with an open-circuit voltage (Voc) of 0.4 V and short-circuit current density (Jsc) of about 15 mA/cm2 under AM1.5 (100 mW/cm2) illumination. From the calculation, the energy conversion efficiency and fill factor were found to be 2.1% and 0.38, respectively. The carbon layer contributed to the energy conversion efficiency, which was proved by the measurement of quantum efficiency.