High-bandwidth organic photodetector analyzed by impedance spectroscopy Articles uri icon

publication date

  • October 2012

start page

  • 1868

end page

  • 1871


  • 20


  • 24

International Standard Serial Number (ISSN)

  • 1041-1135

Electronic International Standard Serial Number (EISSN)

  • 1941-0174


  • An organic bulk heterojunction photodetector (OPD) is fabricated on the basis of a blend of poly(3-hexyl thiophene):1-(3-methoxycarbonyl)-propyl-1-1-phenyl-(6,6) C61. The OPD responsivity is calculated from current density-voltage characteristic (J-V) under green-LED illumination obtaining 1 A/W. Frequency response at different biases is measured, which shows a high -3-dB cutoff frequency of 343 kHz at -3 V. Impedance measurements are carried out at different reverse biases, and the results are fitted with a small signal equivalent circuit. The device cutoff frequency (f(c)) can be estimated with the parameters extracted from this circuit obtaining good agreement between measured and calculated f(c).


  • bulk heterojunction; cutoff frequency; impedance spectroscopy; organic photodetector; deep-ultraviolet photodetector; solar-cells