Abstract
As organic-inorganic halide perovskite solar cells (PSCs) near commercialization, stability challenges during real-world conditions, such as durability at elevated temperatures, still need to be addressed. We have previously reported that doping of triarylamine-based hole-transport layers (HTLs) with a triarylamine-based radical cation salt (EHCz-3EtCz/EH44-ox) leads to enhanced PSC stability at elevated temperatures. While it was shown the radical cation dopant did not need to be identical to the HTL matrix, little was known about dopant exchange to realize the maximum impact on device-level properties (e.g., increase in low intrinsic conductivity, mobility, hydrophobic properties, ease of synthesis, and thermal stability). In this paper, we study the impact of dopant exchange among stable, low-cost, high-glass-transition temperature (Tg), and easily synthesized triarylamine-based HTL and radical triarylamine cation salts as dopants. Using EH44-ox as dopant leads to the improved device-level power conversion efficiency (PCE) for all HTL matrices assessed. Moreover, increasing the number of ethylhexyl chains from one to two per molecule and positioning these chains at the periphery rather than the core resulted in improved hydrophobicity. PSCs based on our HTL formulations have similar power conversion efficiencies (PCE) as those of PSCs based on commercially available HTLs while demonstrating greatly improved device-level stability at elevated temperatures.
Original language | American English |
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Pages (from-to) | 4492-4498 |
Number of pages | 7 |
Journal | ACS Applied Energy Materials |
Volume | 3 |
Issue number | 5 |
DOIs | |
State | Published - 26 May 2020 |
Bibliographical note
Publisher Copyright:Copyright © 2020 American Chemical Society.
NREL Publication Number
- NREL/JA-5900-76368
Keywords
- dopant exchange
- EH44-ox
- EtCz-3EHCz
- hole-transport layers
- perovskite solar cells