Hot Casting Method to Create Pb-Free, Sn-Based Perovskite Films with Reduced Pinholes

Overview

Hybrid organic–inorganic lead halide perovskite solar cells, PVSCs, have emerged in the past decade as a promising, low cost, thin film photovoltaic device with the power conversion efficiency (PCE) increasing from 3.8% to 22.7%. However, poor long-term stability of PVSCs and the toxic properties of lead limits future commercial applications. Fabrication of uniform perovskite films with full coverage and fewer pinholes are the prerequisites for achieving a high-performance perovskite. To achieve a good film morphology, one-step solution processing and anti-solvent engineering was used. All precursors (FaI and SnI2) were dissolved in DMSO and GBL. 10% SnF2 was also added to suppress the formation of Sn4+. Before putting in the spin coater, the precursor solution and the glass substrates were heated to 60℃, 70℃, 80℃, 90℃, and 100℃. During spin coating, the anti-solvent wash with toluene was performed to removed excess DMSO. After spin-coating, the perovskite glass substrate was annealed at 100 degrees Celsius. Perovskite layers were characterized by X-Ray Diffraction (XRD) and its surface morphology was investigated by a Scanning Electron Microscope (SEM). From the SEM pictures, it was concluded that 70℃ was the optimal temperature for the precursor to create a pinhole free perovskite layer. Through the XRD peak analysis, morphology and crystallinity of the structure was analyzed and confirmed to have stable and simple cubic structure with a lattice constant of 4.09A. The next step in this project is to find a better annealing temperature to reduce more pinholes and to try Cesium instead of Formamidinium.

Competition history

• AJAS 2020 Category not listed

Related projects

Closest projects by meaning, across every fair and year in the corpus.

Browse more like this

• All Energy and Transport projects
• AJAS Energy and Transport projects
• Every AJAS 2020 project