How to Achieve High Spatial Resolution in Organic Optobioelectronic Devices?

How to Achieve High Spatial Resolution in Organic Optobioelectronic Devices?

Článek WoS

Light activated local stimulation and sensing of biological cells hold great promise for minimally invasive bioelectronic interfaces. Organic semiconductors are particularly appealing for these applications due to their optoelectronic properties and biocompatibility. This study examines the material properties necessary to localize the optical excitation and achieve optoelectronic transduction with high spatial resolution. Using photovoltage and photocurrent microscopy, we investigate spatial broadening of local optical excitation in Phthalocyanine/3,4,9,10-Perylenetetracarboxylic diimide (H2PC/PTCDI) planar heterojunctions. Our measurements reveal that resolution losses are tied to the effective diffusion length of charge carriers at the heterojunction. For the H2PC/PTCDI heterojunction, the diffusion length is determined to be lambda d = 1.5 +/- 0.1 mu m, attributed to reduced carrier mobility. Covering the heterojunction with poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) improves the charge generation performance but increases the carrier diffusion length to lambda d = 7.0 +/- 0.3 mu m due to longer lifetime and higher carrier mobility. These findings elucidate the physical mechanisms underlying transduction and provide design principles for organic semiconductor devices aimed at achieving high efficiency and high spatial resolution for wireless and optically activated bioelectronics.

Light activated local stimulation and sensing of biological cells hold great promise for minimally invasive bioelectronic interfaces. Organic semiconductors are particularly appealing for these applications due to their optoelectronic properties and biocompatibility. This study examines the material properties necessary to localize the optical excitation and achieve optoelectronic transduction with high spatial resolution. Using photovoltage and photocurrent microscopy, we investigate spatial broadening of local optical excitation in Phthalocyanine/3,4,9,10-Perylenetetracarboxylic diimide (H2PC/PTCDI) planar heterojunctions. Our measurements reveal that resolution losses are tied to the effective diffusion length of charge carriers at the heterojunction. For the H2PC/PTCDI heterojunction, the diffusion length is determined to be lambda d = 1.5 +/- 0.1 mu m, attributed to reduced carrier mobility. Covering the heterojunction with poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) improves the charge generation performance but increases the carrier diffusion length to lambda d = 7.0 +/- 0.3 mu m due to longer lifetime and higher carrier mobility. These findings elucidate the physical mechanisms underlying transduction and provide design principles for organic semiconductor devices aimed at achieving high efficiency and high spatial resolution for wireless and optically activated bioelectronics.

optobioelectronics; organic heterojunctions; photocapacitors; photocurrent microscopy; photovoltage; spatial resolution

optobioelectronics; organic heterojunctions; photocapacitors; photocurrent microscopy; photovoltage; spatial resolution

FABBRI, L.; MIGLIACCIO, L.; ŠIRVINSKYTĖ, A.; RIZZI, G.; BONDI, L.; TAMAROZZI, C.; WEBER, S.; FRABONI, B.; GLOWACKI, E.; CRAMER, T.

01.05.2025

WILEY

HOBOKEN

2196-7350

Advanced Materials Interfaces

12

9

Spolková republika Německo

1

9

9

https://advanced.onlinelibrary.wiley.com/doi/10.1002/admi.202400822

http://hdl.handle.net/11012/250922

Manuscript_Revised postprint
2025-Fabbri