2D - 3D Hybrid perovskites for perovskite solar cells

Abstract

Hybrid Organic-Inorganic Perovskites (HOIP) have been studied extensively and grown popular. Especially in Three-dimensional (3D) Perovskites, achieving power conversion efficiency (PCE) exceeds 23%. Nevertheless, some of the morphological imperfections will limit their structural capabilities. Pinholes in discontinuous perovskite films induces the huge leakage current which can cut down the device efficiency and creates a short circuit. Therefore, it is essential to deposit a compact film with passivated defects. Two-dimensional (2D) halide perovskites, conversely attracted significant attention and become a positive alternative with their uncomplicated synthesis, stability, and excellent photoelectric properties. This study, investigates the formation and properties of 2D Tetrabutylammonium lead halide (TBAPbBrxI3-x) HOIP. Tetrabutylammonium ion is a large cation, and more likely forms a 2D perovskite structure which was confirmed by the XRD spectrum. Substantiate by SEM images, TBAPbBrxI3-x establishing and favors crystals with enhance orientation and few grain boundaries and. However, the absorption spectra of the film shows an excitonic peak at 411 nm and a clear band edge at 450 nm. Resulting in poor absorbance in the visible range, with optical band gap of 2.76 eV, narrowing the ability to use TBAPbBrxI3-x alone in solar cells. Conversely, TBAPbBrxI3-x can use as separate capping layer on the top of 3D perovskite layer, enhancing the properties of the 3D perovskite layer. Incorporating TBAPbBrxI3-x into CH3NH3PbI3 shows a better film formation with few holes. The application of mixed perovskite layers incorporated solar cells will result in better structural and optoelectronic properties.