화학공학소재연구정보센터
Solar Energy, Vol.173, 496-503, 2018
Nanostructured ZnO electron transporting materials for hysteresis-free perovskite solar cells
ZnO and Indium-doped (In-doped) ZnO nanocrystals with four different morphologies including nanodisks, nanorods, nanotripods, and nanochips were synthesized via simple and low-temperature hydrothermal route. The associated morphologies and structures of the as-prepared nanocrystals were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and transmission electron microscopy (TEM). The results showed that reaction temperature played a vital role in the formation of ZnO morphologies, and accordingly, zinc to indium molar ratio was proposed. The obtained In-doped ZnO morphologies were used as an electron transporting materials (ETMs) in perovskite solar cells (PSCs), and the photovoltaic results showed that the short-circuit-current-density (J(sc)) and the average power conversion efficiency (PCEavg) of the nanochips based PSCs were 21.9 mA cm(-2) and 15.17%, respectively, which were largely enhanced compared with those of the nanodisks based PSCs (18.2 mA cm(-2) and 11.18%). The substantial enhancement for the former was thanks to the sufficient perovskite absorber loading, better morphology and crystallinity. Furthermore, a conformal coating of PEI was applied on the surface of electron-rich In-doped ZnO nanochips, causing a favorable work function shift and overall leading to the significant boost in efficiency from < 15% up to > 18%.