Investigation of Thermal Instability of Additive-Based High-Efficiency Organic Photovoltaics

Most photovoltaics operate at high temperature under sunlight. In this work, the thermal instability of diiodooctane-based high-efficiency bulk heterojunction (BHJ) organic photovoltaics (OPVs) is studied. The BHJ layers were heated to various temperatures to investigate the changes in their physical properties using atomic force microscopy phase images. The mobilities of the carriers were characterized at various temperatures using the space-charge-limited current method, and the carrier lifetime was calculated by applying impedance spectroscopy to the simulated equivalent circuit of the OPV devices.