Showing papers by "Yanxia Cui published in 2021"

Interface modification of an electron transport layer using europium acetate for enhancing the performance of P3HT-based inorganic perovskite solar cells.

Abstract: In recent years, although the power conversion efficiency (PCE) of thermally stable all-inorganic CsPbI3 perovskite solar cells (PSCs) had shown a great progress, the most reported CsPbI3 PSCs suffered from the large open-circuit voltage (Voc) loss, which is related to severe nonradiative recombination and a mismatch in energy level at the transport layer/perovskite interface. In this work, europium acetate (EuAc3) as a multifunction interface material is chosen to modify the TiO2/perovskite interface, the crystal quality of CsPbI3 perovskite films is improved, and both bulk and interfacial defects are reduced effectively. Meanwhile, the energy levels arrangement between TiO2 and CsPbI3 perovskites is also optimized, corresponding the raised built-in electric field afford a strength force to accelerate the transport and extraction of charge carriers from CsPbI3 perovskites to TiO2. As a result, the performance of CsPbI3 PSCs is largely enhanced with the PCE of 16.76%. When an Ag electrode was replaced by Au, the PCE further improves to 17.92%, which is the highest for CsPbI3 PSCs with P3HT as the HTL ever reported. Besides, the CsPbI3 PSC with the EuAc3 modification layer maintains 84% of the initial PCE under continuous UV irradiation for 250 h in a nitrogen filled glovebox, being obviously higher than the control devices with only 40% of the initial PCE after UV irradiation for 100 h in the same environment.

Application of quantum dots in perovskite solar cells

Abstract: Perovskite solar cells (PSCs) are important candidates for next-generation thin-film photovoltaic technology due to their superior performance in energy harvesting. At present, their photoelectric conversion efficiencies (PCEs) are comparable to those of silicon-based solar cells. PSCs usually have a multi-layer structure. Therefore, they face the problem that the energy levels between adjacent layers often mismatch each other. Meanwhile, large numbers of defects are often introduced due to the solution preparation procedures. Furthermore, the perovskite is prone to degradation under ultraviolet (UV) irradiation. These problems could degrade the efficiency and stability of PSCs. In order to solve these problems, quantum dots (QDs), a kind of low-dimensional semiconductor material, have been recently introduced into PSCs as charge transport materials, interfacial modification materials, dopants and luminescent down-shifting materials. By these strategies, the energy alignment and interfacial conditions are improved, the defects are efficiently passivated, and the instability of perovskite under UV irradiation is suppressed. So the device efficiency and stability are both improved. In this paper, we overview the recent progress of QDs' utilizations in PSCs.

Maxwell's demon-like nonreciprocity by non-Hermitian gyrotropic metasurfaces

Abstract: The authors propose a non-Hermitian metasurface that functions as a photonic Maxwell's demon, which is a variation of Maxwell's demon which controls photons instead of gas particles.