Perovskite single crystals for solar cell and photodetector

  • Chen Yang

Student thesis: Doctoral Thesis

Abstract

Lead halide perovskite solar cells (PSCs) are considered the next generation of photovoltaic technology, reaching an outstanding certified power conversion efficiency of 25.7% in just 20 years. The best-performing PSCs are based on polycrystalline films, where the presence of grain boundaries and a tremendous number of defects limit stability and efficiency and thus further industrial development. Compared to their polycrystalline counterparts, single crystals of lead halide perovskites have been shown to possess much lower trap-state densities, long diffusion lengths, high stability, and near-IR absorption. This thesis describes the use of a confined space and inverse temperature method to grow perovskite single crystals of MAPbI3 directly on PTAA (poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine]) films. This method allowed the fabrication of p-i-n inverted solar cells with the structure ITO/PTAA/perovskite single-crystal thin film/C60 (fullerene)/BCP (bathocuproine)/Cu (copper). A key requirement in achieving high photoconversion efficiency (PCE) is avoiding iodine oxidation, which forms triiodide impurities that function as defects in perovskites and that can seriously hinder the performance of perovskites. By suppressing the formation of triiodide, high-quality perovskite photodetectors and solar cells can be realized. For single crystals, orientation has a strong effect on device performance. Here, (100)- and (001)-facet single-crystal thin films were fabricated into solar cells. Unlike traditional (100)-facet films, which exhibit high PCE in a glovebox environment, (001)-facet single-crystal thin films show high stability under ambient conditions.
Date of AwardAug 28 2022
Original languageEnglish (US)
Awarding Institution
  • Physical Science and Engineering
SupervisorOmar Mohammed Abdelsaboor (Supervisor)

Keywords

  • Perovskite
  • single crystals
  • orientation
  • solar cells
  • photodetector

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