| 초록 |
We investigate the effect of ionic liquid molecules (ILMs) in quantum dot-organic hybrid solar cells. The insertion of an ILMs layer between PbS and PCBM can shift the band edge of PCBM closer to the vacuum level of PbS due to spontaneous dipole polarization. Owing to this new architecture, improvements in device performance were achieved, including an increase in VOC from 0.41 V to 0.49 V, FF from 0.48 to 0.59 and PCE from 1.62% to 2.21% compared to reference devices under AM 1.5G illumination at 100 mW cm-2. We observed that treatment of the PbS layer with ILMs causes a significant increase in work function from 3.58 eV to 3.93 eV. Furthermore, the ILMs layer minimizes the contact resistance between PbS and PCBM due to the improved compatibility between the two layers, confirmed as a decrease in charge transfer resistance as measured by electrical impedance spectroscopy. Furthermore, we have also investigated the effect of an optical cavity on the performance of colloidal quantum dot solar cells. For the study, a zinc oxide layer is incorporated to serve as the optical cavity layer in an inverted structure. Notably, enhanced light absorption was achieved by optimizing the optical field distribution within the active layer in the inverted device configuration, leading to improved photovoltaic device performance. Comprehensive characterization and optical modeling of the resulting devices is performed to understand the effect of optical cavities and device geometry on photovoltaic performance. |
