Scientists develop method to decrease the formation of anions vacancy defects in halide perovskite solar cells

• Researchers at China's Shaanxi Regular University and Chinese Academy of Sciences (CAS) have actually designed a novel approach to reduce the formation of anions vacancy defects in halide perovskite solar cells. The team reported that the new strategy leads to greater performance and impressive stability.

The new method, which they specified as 'a one-stone-for-two-birds' approach, used a ligand called 3-amidinopyridine (3AP) to pin anions in the device. Anions can control the nucleation as well as growth of the perovskite crystals and work as a passivating agent to improve the crystallinity, therefore guaranteeing improved efficiency. The group states the 3AP molecules deposited on the perovskite layer have the ability to develop strong chemical bonds with the cell's lead(II) iodide (Pb-- I) interlayer and also, consequently, create a lasting pinning result.

"We located that 3AP molecules were arranged in parallel and also anti-symmetrically between Pb-- I structures with a short interlayer distance of 3.45 angstrom(Å), which is much shorter than that obtained for previously reported ligands, resulting in one-of-a-kind control within the crystals," the scientists discussed.

The team constructed the cell with a substrate constructed from tin oxide (FTO), a titanium oxide (TiO2) electron transport layer, a halide perovskite called α-formamidinium lead iodide (α-FAPbI3), a spiro-OMeTAD hole transport layer, and gold (Au) metal contact.

They evaluated the efficiency of the device via density functional concept (DFT) computations and compared it with that of a recommendation cell utilizing generally made use of large organic ligands such as 2-phenethylammonium (PEA) and also n-butylammonium (BA).

The group located that the 3AP-based cell attained a maximum power conversion efficiency of 25.3%, an open-circuit voltage of 1.181 V, a short-circuit current of 26.04 mA centimeters − 2, and also a fill variable of 82.21%. The reference cell without 3AP molecules got to an effectiveness of 22.76%, an open-circuit voltage of 1.123 V, a short-circuit current of 24.94 mA cm − 2, and a fill element of 81%.

Through additional measurements, the scientists likewise located that a 3AP-based cell without encapsulation was able to retain 92% of its initial effectiveness after 5000 h exposure at ambient problems. "The anion-vacancy defect engineering via solid molecule-- perovskite sychronisation provides an effective and simple service for enhancing both the effectiveness and stability of perovskite solar cells," they stated.

"Our findings offer a reliable chemical approach for the facile construction of high-performance steady perovskite solar cells and are possibly appropriate to various other perovskite optoelectronic devices," the group wrapped up.