Improvement Properties of Hybrid Halide Perovskite Thin Films Prepared by Sequential Evaporation for Planar Solar Cells

Abstract

Thin films of CH3NH3PbI3 and (NH2)2CHPbI3 (from now on abbreviated as MAPI and FAPI respectively), with perovskite structure were prepared by sequential evaporation of lead iodide (PbI2) and methylammonium iodide (MAI) or formamidinium iodide (FAI), with special emphasis on the optimization of its optical, morphologic, and structural properties. For this, the evaporation process was automatically controlled with a system developed using virtual instrumentation (VI) that allows electronic control of both evaporation sources temperature and precursors deposition rates, using proportional integral derivative (PID) and pulse width modulation (PWM) control algorithms developed with the LabView software. Using X-ray diffraction (XRD), information was obtained regarding the phase and crystalline structure of the studied samples as well as the effect of the main deposition parameters on crystallite size and microstrain. We also studied the influence of the main deposition parameters on the optical and morphological properties through measurements of spectral transmittance and scanning electron microscopy (SEM) respectively. It was found that the implemented method of sequential evaporation allows preparing, with a high degree of reproducibility, single phase MAPI and FAPI thin films with appropriate properties to be used as active layer in hybrid solar cells. The applicability of MAPI and FAPI thin films as active layer in photovoltaic devices has been demonstrated by using them in solar cells with structure: FTO/ZnO/MAPI(or FAPI)/P3HT/Au.

Roles of Inorganic Oxide Based HTMs towards Highly Efficient and Long-Term Stable PSC—A Review

“…The tunable optical properties make it easier to experiment with device performance and improve PSCs’ overall performance [ 68 ]. On the other hand, perovskite films can be prepared by versatile low cost and simple film deposition methods, such as spin-coating [ 69 , 70 ], sequential deposition [ 71 , 72 ], and evaporation [ 73 , 74 ] techniques. Low-temperature spin coating is the simplest method to fabricate low-cost and high-efficiency PVSC devices.…”

Improving Photostability of Cesium-Doped Formamidinium Lead Triiodide Perovskite

“…Pure polycrystalline FAPbI 3 is relatively featureless from 400 to 800 nm, 41 whereas MHPs grown with excess FAI in a vacuum and in solution have been reported to produce materials with second-phase inclusions. 42,43 Analysis of the absorptance data in Figure 1B shows that the observed increase below 600 nm is coincident with decreased absorptivity at the band edge when excess FAI is present. Therefore, excess FAI consumes FAPbI 3 , forming second-phase inclusions (e.g., I 2 , FA 2 PbI 4 ).…”

Paper-Based Stable Broad Band Optical Detector Made from Mixed Cation Organic Perovskite Halides

“…A comparison of the optical response of a detector made from cation-substituted MA 0.6 FA 0.4 PbI 3 has been made with those made from unsubstituted single cation halide perovskites MAPI and FAPI. MAPI has a band gap of ∼1.6 eV (775 nm), and FAPI has a band gap of ∼1.49 eV (832 nm) . Absorbance data are shown in Figure .…”

“…MAPI has a band gap of ∼1.6 eV (775 nm), and FAPI has a band gap of ∼1.49 eV (832 nm). 40 Absorbance data are shown in Figure 10. MAPI and the mixed halide have very close absorbance and the absorption edge, while that for FAPI is red-shifted to longer wavelengths.…”