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

publication date

  • octubre 2012

start page

  • 1868

end page

  • 1871

issue

  • 20

volume

  • 24

international standard serial number (ISSN)

  • 1041-1135

electronic international standard serial number (EISSN)

  • 1941-0174

abstract

  • 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).

keywords

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