Thiophene-modified perylenediimide as hole transporting material in hybrid lead bromide perovskite solar cells

Jaykrushna Das, Raja Bhaskar Kanth Siram, David Cahen, Boris Rybtchinski, Gary Hodes

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16 Citations (Scopus)

Abstract

A small molecule based on N,N′-dialkyl perylenediimide (PDI) as core derivatized with thiophene moieties (Th-PDI) was synthesized. Its HOMO (highest occupied molecular orbital) level was measured to be between 5.7 and 6.3 eV vs. local vacuum level depending on doping and measurement method. Th-PDI was successfully applied as hole-transporting material (HTM) in CH3NH3PbBr3 hybrid perovskite solar cells. Three different cell architectures, each with a different mode of operation, were tested: (1) using a mesoporous (mp) TiO2 substrate; (2) mp-Al2O3 substrate; (3) planar dense TiO2 substrate. The first gave the best overall efficiency of 5.6% while the mp-Al2O3 gave higher open-circuit photovoltage (VOC) but lower efficiency (2.2%). The cells exhibited good reproducibility with very little J-V hysteresis (the mp-Al2O3 showed a more appreciable hysteresis of individual photovoltaic parameters but little dependence of efficiency on scan direction). Storage of unencapsulated cells in 25-30% relative humidity demonstrated fairly good stability with <20% efficiency drop after 37 days. While further optimization of each layer in the device is needed, the synthetically-simple new molecule shows promise as an inexpensive and readily-doped HTM for use in photovoltaic cells where a deep HOMO level is needed.

Original languageEnglish
Pages (from-to)20305-20312
Number of pages8
JournalJournal of Materials Chemistry A
Volume3
Issue number40
DOIs
Publication statusPublished - Jan 1 2015

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ASJC Scopus subject areas

  • Chemistry(all)
  • Renewable Energy, Sustainability and the Environment
  • Materials Science(all)

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