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A Smart Photochromic Semiconductor: Breaking the Intrinsic Positive Relation Between Conductance and Temperature
Author(s) -
Sun Cai,
Yu XiaoQing,
Wang MingSheng,
Guo GuoCong
Publication year - 2019
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201904121
Subject(s) - semiconductor , electron transfer , conductivity , organic semiconductor , chemistry , intermolecular force , photochromism , radical ion , chemical physics , photochemistry , photoinduced electron transfer , nanotechnology , materials science , optoelectronics , organic chemistry , ion , molecule
Breaking the intrinsic rule of semiconductors that conductivity increases with increase of temperature and realizing a dramatic dropping of conductivity at high temperature may arouse new intriguing applications, such as circuit overload or over‐temperature protecting. This goal has now been achieved through T‐type electron‐transfer photochromism of one organic semiconductor assembled by intermolecular cation⋅⋅⋅π interactions. Conductivity of the viologen‐based model semiconductor (H 2 bipy)(Hox) 2 (H 2 bipy=4,4′‐bipyridin‐1,1′‐dium; ox=oxalate) increased by 2 orders of magnitude after photoinduced electron transfer (a record for photoswitchable organic semiconductors) and generation of radical cation⋅⋅⋅π interactions, and fell by approximately 81 % at 100 °C through reverse electron transfer and degeneration of the radical cation⋅⋅⋅π interactions. The model semiconductor has at least two different electron transfer pathways in the decoloration process.