Abstract
We report an analysis of the ac response of a bulk-heterojunction solar cell in a standard architecture made of an anthracene containing poly(p-arylene-ethynylene)-alt-poly(p-arylene-vinylene)/1-(3 methoxy carbonyl) propyl-1-phenyl[6,6] and C60 (AnE-PVstat:PCBM) blend, these were made in detail at room temperature. Impedance spectroscopy is showing “backwards” arcs in Cole–Cole figures at low frequencies that are interpreted through equivalent circuit using negative resistances for electrical contacts. This equivalent circuit model incorporated chemical capacitance (Cμ), recombination resistance (Rrec), transport resistance (Rt) and contact electrical resistance (Rco). We have taken Rco as negative values in the bipolar regime to theoretically reproduce the small arc shown in the Nyquist plots. In addition, negative capacitance (NC) was observed under positive dc biases in the bipolar regime. The recombination time τrecdecreases with increasing bias voltages. This result is in agreement with the direct Langevin-type bimolecular recombination. We determined the diffusion time (τdif) and the diffusion length (Ln) and other parameters. Average mobility of global carriers for the device is around 410−3cm2V−1s−1 which is in good agreement with that derived using PCBM electron-only devices.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.