| 초록 |
One of the promising approaches to surpass the Shockley-Queisser efficiency limit of single p-n junction photovoltaic devices is to configure the multi-junction in a cell. Tandem architectures that are composed of the multiple cells with different bandgaps can provide a useful strategy to minimize severe photon energy loss by carrier thermalization, resulting in an enhanced power conversion efficiency beyond the performance of single-junction solar cells. While there are many bottom cell candidates with low bandgap energies, e.g., Si and CuInSe2 (CISe), however, the absence of appropriate top cell candidates with suitable bandgap as well as high performance has impeded the progress of tandem devices. Since the first report on perovskite-based solar cells, they have quickly been recognized as a potential top cell candidate due to their several advantages, including high efficiency, outstanding optoelectronic properties, bandgap tunability, and low-cost processing. In this study, we aim to demonstrate double-junction monolithic tandem solar cells (perovskite/CISe and perovskite/Si) in a cost-effective manner. The single-junction semi-transparent perovskite solar cell with an inverted configuration was first demonstrated, where the role of nanoparticulated ZnO layers between the electron-extracting PCBM and top transparent conducting oxide electrode was investigated in depth. The semi-transparent perovskite top cell was then directly fabricated onto the bottom cells to construct the monolithic tandem devices. In addition to solution processible perovskite top cells, electrodeposited CISe thin-film solar cells and standard Al-back surface field p-type Si solar cells were used as narrow bandgap bottom cells, respectively, which can provide the potential for constructing the low-cost tandem devices. |
