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Voltage controlled bio-organic inverse phototransistor
Esha Mishra1, Thilini K Ekanayaka1, Peter A Dowben1
1Department of Physics and Astronomy, University of Nebraska-Lincoln, Jorgenson Hall, 855 North 16th Street, Lincoln, Nebraska 68588-0299, USA.
Biointerphases
|March 19, 2022
Summary
Poly-d-lysine thin films exhibit light sensitivity and act as inverse phototransistors, with current decreasing upon illumination. This indicates hindered photoexciton unbinding and significant charge carrier lifetime in these polar organic films.
Area of Science:
- Materials Science
- Organic Electronics
- Photophysics
Background:
- Poly-d-lysine thin films are polar organic materials with inherent light sensitivity.
- Understanding their photoresponse is crucial for developing novel electronic devices.
Purpose of the Study:
- To investigate the photoresponse of poly-d-lysine thin film devices.
- To evaluate the effect of methylene blue as an additive on device performance.
Main Methods:
- Fabrication of poly-d-lysine thin film transistors.
- Characterization using capacitance-voltage (C-V) and current-voltage (I-V) measurements.
- Analysis of transistor behavior under varying illumination conditions.
Main Results:
- Poly-d-lysine transistors function as inverse phototransistors, with maximum current in darkness.
- Illumination leads to decreased capacitance and transistor current, irrespective of methylene blue presence.
- Significant charge carrier lifetime observed, suggesting hindered photoexciton unbinding.
Conclusions:
- Poly-d-lysine thin films possess unique inverse phototransistor characteristics.
- Methylene blue does not alter the fundamental photoresponse mechanism.
- Device performance is influenced by gate voltage-dependent majority carrier behavior and film polarization.
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