Organic-inorganic hybrid perovskite materials offer the potential for realization of low-cost and flexible next-generation solar cells fabricated by low-temperature solution processing. Although efficiencies of perovskite solar cells have dramatically improved up to 22.1% within the past 6 years, there is still considerable room for further improvement in device efficiency through development of smooth and large grain size perovskite films. Commonly, the smooth perovskite layers and large grains are alternative to CH3NH3PbI3-xClx. However, the previous one-step fabrication of CH3NH3PbI3-xClx using PbCl2 needs long annealing time. Herein, the active layer, a noncontinuous CH3NH3PbI3-xClx film with micrometre-level crystalline grain, was fabricated using a one-step spin-coating process followed by high-temperature annealing and exhibited an increased efficiency of 9.93%. This finding enables the formation of larger grain size perovskite films and the demonstration of efficient perovskite heterojunction solar cells.
Ion Transport, Defect Chemistry, and the Device Physics of Hybrid Perovskite Solar Cells