# Organic Phototransistor Photonic Synapses for Artificial Vision

## TL;DR

This paper reviews recent advances in organic phototransistor-based photonic synapses for artificial vision, focusing on materials, behaviors, and applications.

## Contribution

The paper provides a comprehensive and in-depth review of bidirectional photoresponse mechanisms and material–structure–function correlations in organic phototransistor synapses.

## Key findings

- Organic phototransistors exhibit negative photoconductance and information-erasing capabilities.
- OPT-based synapses enable applications like human visual adaptation and multimodal neuromorphic encryption.
- OPTs offer advantages such as high bandwidth and low energy consumption for neuromorphic computing.

## Abstract

The latest progress in neuromorphic artificial synapses based on organic phototransistors is reviewed from three aspects: functional semiconductor materials, operating behaviors, and frontier applications/advancements.The negative photoconductance behavior of novel phototransistors is discussed, along with their fascinating information-erasing capabilities demonstrated in organic photonic synapses.Frontier applications and advancements in neuromorphic vision driven by organic photonic synapses, such as human visual adaptation, polarization-sensitive detection, high-dimensional reservoir computing, and multimodal neuromorphic encryption, are demonstrated.

The latest progress in neuromorphic artificial synapses based on organic phototransistors is reviewed from three aspects: functional semiconductor materials, operating behaviors, and frontier applications/advancements.

The negative photoconductance behavior of novel phototransistors is discussed, along with their fascinating information-erasing capabilities demonstrated in organic photonic synapses.

Frontier applications and advancements in neuromorphic vision driven by organic photonic synapses, such as human visual adaptation, polarization-sensitive detection, high-dimensional reservoir computing, and multimodal neuromorphic encryption, are demonstrated.

The von Neumann architecture faces significant limitations,
including low transmission efficiency and high energy consumption, when
handling large-scale data and unstructured problems. Benefiting from the
inherent merits of optical signals including high bandwidth, near-zero
Joule heating, fast transmission speed, and immunity to electromagnetic
interference, photonics provides a powerful pathway for high-speed neuromorphic
computing. Together with the mechanical flexibility and largearea
manufacturability of organic semiconductors, organic phototransistor
(OPT)-based photonic synapses have therefore attracted extensive attention
in recent years. This review provides a comprehensive overview of recent
advances in OPT-based photonic synapses, covering operational principles,
active materials, advances in bidirectional photoresponse process, as well
as cutting-edge applications. Finally, the current challenges and opportunities
in this field are highlighted. Distinct from previous reviews, this review emphasizes an in-depth exploration of bidirectional photoresponse
mechanisms, a systematic dissection of material–structure–function correlations enabling integrated sensing-memory technology, and emerging.