Research

Deposition techniques influence film crystallography, morphology, stoichiometry, and degradation, and each type of deposition requires different conditions to optimize films. In my previous work, I investigated crystallography, morphology, stoichiometry, and degradation of perovskite thin films fabricated by various deposition techniques. For comparison, I used only DMF as a solvent. X-ray photoelectron spectroscopy (XPS), x-ray diffraction (XRD), and scanning electron microscopy (SEM) were employed to better understand perovskites' oxidation, film crystallography, morphology, and stoichiometry. Time-resolved photoluminescence (TRPL) and photoluminescence (PL) allowed me to interpret the lifetime and bandgap of the perovskite material. My UV-Vis spectrophotometer results allowed me to investigate the influence of various deposition techniques on perovskite optoelectronic properties.

In this work, four different deposition techniques—(i) one-step deposition, (ii) two-step deposition, (iii) room-temperature solvent-to-solvent extraction (SSE), and (iv) solution processing using FA/MA mixed cations were considered. Planar heterojunction perovskite solar cells (PSCs) were fabricated using the most effective deposition technique based on different characterizations. To optimize the electron-transport layer, I systematically investigated how the thickness of the compact TiO2 layer affects device performance by using different spin speeds to fabricate this layer. In addition, I compared device performance between well-studied TiO2 and low-temperature solution-processed nanocrystalline SnO2 as the electron-transport layer. 

Accomplishment 

• Achieved 16.74% power conversion efficiency (PCE) with open-circuit voltage (Voc) of 1.01 V, short circuit current density (Jsc) of 24 mA/cm^2, and fill factor (FF) of 69.40% for TiO2 based organic-inorganic mixed halide perovskite solar cell.

•  Achieved 18.75% power conversion efficiency (PCE) with open-circuit voltage (Voc) of 1.086 V, short circuit current density (Jsc) of 24.69 mA/cm^2, and fill factor (FF) of 69.87% for SnO2 based organic-inorganic mixed halide perovskite solar cell.