A sandwich device has been fabricated from DNA molecular film by solution processing located between Al and p-type silicon inorganic semiconductor. We have performed the electrical characteristics of the device such as current-voltage (I-V), capacitance-voltage (C-V) and capacitance-frequency (C-f) at room temperature and in dark. The DNA-based structure has showed the rectifying behavior. From its optical absorbance spectrum, it has been seen that DNA has been a semiconductor-like material with wide optical band energy gap of 4.12 eV and resistivity of 1.6 x 10(10) Omega cm representing a p-type conductivity. (C) 2008 Elsevier B.V. All rights reserved.