We report novel photovoltaic (PV) switching based on the low exciton-binding energy property of an organic heptazole (C26H16N2) thin film after fabrication of an heptazole-based Schottky diode. The Schottky diode cell displayed an instantaneous voltage of 0.3 V as an open circuit voltage (VOC) owing to the work function difference between the Schottky and ohmic electrode under deep blue illumination. Four tandem diode cells therefore produced ∼ 1.2 V. As a PV diode circuit can be formed using an even number of diodes, a photo-excited charge accumulation takes place, generating VOC in the central electrode of the tandem diode array by illuminating one half of the array. An electron-hole recombination then also takes place in that electrode by illuminating the other half, making the VOC decrease to 0 V. Utilizing this charge accumulation and recombination under deep blue illumination, we successfully demonstrated quite fast PV optical switching, logic gating and, ultimately, the gate switching of an organic field-effect transistor. We therefore concluded that our self-powered PV-induced switching was novel and promising enough to open a new door for energy harvest-related device applications in organics.
Bibliographical noteFunding Information:
This research was supported by Nano Material Technology Development Program (Grant no. 2012M3A7B4049801), NRL Program (NRF-2014R1A2A1A01004815) and BK 21 plus through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT and Future Planning.
All Science Journal Classification (ASJC) codes
- Modelling and Simulation
- Materials Science(all)
- Condensed Matter Physics