Electric properties of a–C:H/ a–C:N:H/aluminum structure

Abstract

To obtain photovoltaic properties using carbon films without dependence on a Si substrate by drift of carriers, a photovoltaic cell consisted of aluminum (Al) and amorphous carbon films was fabricated. Two types of amorphous carbon were deposited on smooth Al substrates and on n-type Si by radio-frequency chemical vapor deposition. The first layer is nitrogen-doped hydrogenated amorphous carbon ( a–C:N:H) film, and the second layer is hydrogenated amorphous carbon ( a–C:H) film. Nitrogen atoms in a–C:N:H film were introduced as N–H structure. Both type of films were confirmed to be semiconductors on the basis of the temperature dependence of electroconductivity. The a–C:N:H/ n–Si structure exhibited photovoltaic characteristics Furthermore, the a–C:H/ a–C:N:H/Al structure cell also exhibited photovoltaic characteristics with an open-circuit voltage and short-circuit current of 5.5 mV and 0.83 μA/cm − 2 , respectively.