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Near‐Infrared Tandem Organic Photodiodes for Future Application in Artificial Retinal Implants
Author(s) -
Simone Giulio,
Di Carlo Rasi Dario,
Vries Xander,
Heintges Gaël H. L.,
Meskers Stefan C. J.,
Janssen René A. J.,
Gelinck Gerwin H.
Publication year - 2018
Publication title -
advanced materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 10.707
H-Index - 527
eISSN - 1521-4095
pISSN - 0935-9648
DOI - 10.1002/adma.201804678
Subject(s) - materials science , retinal , tandem , photodiode , retinal implant , optoelectronics , visual prosthesis , multielectrode array , infrared , microelectrode , photovoltaic system , biomedical engineering , optics , electrode , medicine , ophthalmology , chemistry , biology , composite material , ecology , physics
Abstract Photovoltaic retinal prostheses show great potential to restore sight in patients suffering from degenerative eye diseases by electrical stimulation of the surviving neurons in the retinal network. Herein, organic photodiodes (OPDs) sensitive to near‐infrared (NIR) light are evaluated as photovoltaic pixels for future application in retinal prostheses. Single‐junction and tandem OPDs are compared. In the latter, two nominally identical single‐junction cells are processed on top of each other, effectively doubling the open‐circuit voltage ( V OC ). Both single‐junction and tandem OPD micropixels can deliver the required charge to stimulate neurons under pulsed NIR light at physiologically safe intensities when connected to stimulating microelectrodes in a physiological saline solution. However, only tandem OPD pixels can cover the entire charge per pulse neural stimulation window due to their higher V OC (≈1.4 V). This demonstrates the viability of high‐resolution retinal prostheses based on flexible OPD arrays.