Fig. 5: Photoischromic molecular switches.

a Schematic of a graphene-diarylethene-graphene reversible photoswitching molecular device (left) and I–V curve of open/closed state and photocurrent response curve(right), reproduced from ref.²²⁶, copyright 2016, with permission from American Association for the Advancement of Science. b Schematic illustration of the electrochemically gated break junction experiment (left) and molecular structure of NDI-BT in the neutral state, radical-anion state and dianion state (right), reproduced from ref.²³¹, copyright 2015, with permission from Wiley. c Schematic illustrating the reversible transformation of a neutral or negatively charged Sn-up molecule via a planar molecule geometry to a Sn-down molecule (left) and time series of tunneling current measured on a Sn-up molecule with open feedback loop (right), reproduced from ref.²³², copyright 2009, with permission from American Chemical Society. d Schematic of the hydrogen tautomerization reaction responsible for the switching (left) and current trajectory was obtained when the tip of STM was located at one end of the molecule (right), reproduced from ref.²³³, copyright 2020, with permission from American Chemical Society. e As the molecule unfolds/refolds, the average conductance reversibly changes over three orders of magnitude, reproduced from ref.²³⁵, copyright 2011, with permission from American Chemical Society. f Schematic of a single-molecule pulling/molecular electronics setup (left) and the change of conductance corresponding to the molecular conformation change (right), reproduced from ref.²³⁶, copyright 2011, with permission from American Chemical Society