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Title: Precise Control of Thermal and Redox Properties of Organic Hole‐Transport Materials
Abstract

We report design principles of the thermal and redox properties of synthetically accessible spiro‐based hole transport materials (HTMs) and show the relevance of these findings to high‐performance perovskite solar cells (PSCs). The chemical modification of an asymmetric spiro[fluorene‐9,9′‐xanthene] core is amenable to selective placement of redox active triphenylamine (TPA) units. We therefore leveraged computational techniques to investigate five HTMs bearing TPA groups judiciously positioned about this asymmetric spiro core. It was determined that TPA groups positioned about the conjugated fluorene moiety increase the free energy change for hole‐extraction from the perovskite layer, while TPAs about the xanthene unit govern theTgvalues. The synergistic effects of these characteristics resulted in an HTM characterized by both a low reduction potential (≈0.7 V vs. NHE) and a highTgvalue (>125 °C) to yield a device power conversion efficiency (PCE) of 20.8 % in a PSC.

 
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NSF-PAR ID:
10077994
Author(s) / Creator(s):
 ;  ;  ;  ;  ;  ;  
Publisher / Repository:
Wiley Blackwell (John Wiley & Sons)
Date Published:
Journal Name:
Angewandte Chemie International Edition
Volume:
57
Issue:
47
ISSN:
1433-7851
Page Range / eLocation ID:
p. 15529-15533
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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