Two-dimensional carbon nitride nanorods for efficient perovskite solar cells

Abstract

The organic-inorganic hybrid perovskite solar cell (PSC) demonstrates outstanding photovoltaic characteristics. High-quality and low-defect perovskite films are the keys to high-performance devices. Antisolvent assisted crystallization (ASAC) has been demonstrated to be an efficient method for producing compact and uniform polycrystalline perovskite films. However, during drop antisolvent to form the perovskite active layer, crystals can grow rapidly, resulting in a large number of defects in the perovskite active layer. This results in lower device performance. The antisolvent plays a crucial role in the quality of the formed perovskite active layer. Therefore, it is important to study and try to modify the antisolvent to obtain low-defect perovskite films to enhance the device's performance. Two-dimensional carbon nitride is easy to prepare, stable, and a typical Lewis base that provides electron pairs for bonding and can be used as an effective adjuvant to control the growth of perovskite crystals. We prepared tunable carbon nitride by a high-pressure, high-temperature solid-phase method and then obtained carbon nitride nanorods by solvent thermal exfoliation of carbon nitride. We used different amounts of carbon nitride nanorods as the dopant of the antisolvent and investigated the effect of the modified antisolvent on the active layer of perovskite and the change in device performance. Consequently, a champion device with a maximum power conversion efficiency of 19.31% is approached, with a fill factor of 75% to 82%, a JSC of 22.22 to 23.39 mA/cm2, and a Voc of 0.95 to 1.00 V.