Thesis

Perovskite solar cells for indoor light harvesting

Creator
Rights statement
Awarding institution
  • University of Strathclyde
Date of award
  • 2024
Thesis identifier
  • T16966
Person Identifier (Local)
  • 201862007
Qualification Level
Qualification Name
Department, School or Faculty
Abstract
  • Perovskite solar cells (PSCs) have shown great promise as the new standard for photovoltaics due to their high power conversion efficiency (PCE) of 26.1%. Perovskite materials are ideal photovoltaic materials due to their tuneable band gaps, wide spectral absorption, and their inexpensive and easy manufacturing process. By being able to tune the band gap, one can tune the band gap of the perovskite material close to the ideal band gap for indoor light harvesting of between 1.8- 2.0 eV. This ideal band gap can give a theoretical efficiency of up to 50% under indoor light conditions. One of the biggest advantages is the affordable and easy manufacturing process which allows for a more economical commercialisation of PSCs. These factors make PSCs ideal candidates as indoor light harvesters, with research currently showing PSCs having a champion PCE of over 40% at low light intensities. This thesis investigated various aspects that have not been explored for PSCs as indoor light harvesters. Firstly, an experimental investigation using conductivity measurements, UV-Vis, X-ray photoelectron spectroscopy (XPS) and near-edge X-ray absorption fine structure spectroscopy (NEXAFS) and computational density functional theory (DFT) and time-dependant density functional theory (TD-DFT) methods were conducted to investigate and understand the effect of doping the low cost hole transport material (HTM), [2,2’,7,7’- tetrakis(N,N-di(4-methoxyphenyl)amino)-spiro-(fluorene-9,9’-xanthene)] (SFX-MeOTAD), with its pre-oxidised form of the HTM, (SFX-(TFSI)2). This allowed for the second study to take place. This was where PSCs were fabricated using methylammonium lead triiodide (MAPI) as an absorber with SFX-MeOTAD doped with SFX- (TFSI)2 at dopant concentrations that were near the optimal dopant concentration found in the first study. Devices were tested under 1 Sun and indoor light conditions at varying light intensities of 200, 500 and 1000 lux. The results showed reliable performance under 1 Sun and indoor conditions. The toxicity of lead is one of the biggest obstacles of PSC commercialisation. The third study consisted of lowering the lead (Pb) contents of the MAPI perovskite precursor with two different antimony (III) iodide (SbI3) stock concentrations to investigate the effect on the crystal structure and device performance under 1 Sun and varying indoor light conditions where it was seen that 0.066 M Sb gave comparable 1 Sun performance and under indoor light conditions showed efficiencies over 20%. The final study investigated replacing the lead in the absorber material altogether. The final study utilised a perovskite-inspired Pb free material, Rb3Bi2I9, and an in depth investigation into the morphology, number of layers and electronic performance of PSCs made were measured to investigate the viability of the perovskite-inspired material as an effective indoor light harvesting absorber, this showed the Rb3Bi2I9 has promise as a lead-free PV material.
Advisor / supervisor
  • Ivaturi, Aruna
Resource Type
Note
  • Previously held under moratorium from 05/06/2024 until 05/06/2025.
DOI
Funder
Embargo Note
  • Access is restricted to Strathclyde users only until 05/06/2029.

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