23 bits optical sensor based on nonvolatile organic memory transistor

Abstract

Polymer electret transistor memory device has stable charge storage and memory properties. Here, we combine a large band gap organic semiconductor dinaphtho[2,3-b:2′,3′-f]thieno[3,2-b]thiophene with the polystyrene electret to form an optical sensor with memory effect. The blue light combined with programming bias leads to a positive threshold voltage shift for more than 100 V while the drain-source current shows a variation of seven orders of magnitude. The dynamic range of current device is up to 23 bits and the photo responsivity is 420 A W−1. The optically programmed transistor can be directly used for high-resolution optical sensor and multi-level data storage applications.

Organic Field‐Effect Transistor for Energy‐Related Applications: Low‐Power‐Consumption Devices, Near‐Infrared Phototransistors, and Organic Thermoelectric Devices

“…[128,129] As introduced in Section 2, the positive shift of V th exponentially increases I DS , and therefore, the EQE of phototransistor is easily larger than 100%. The photoinduced current is the result of two distinct effects: the direct photogenerated current coming from exciton dissociation and the field-effect modulated current due to V th shift.…”

“…In addition, the photogenerated electrons can be captured by electron-trapping sites inside the organic layer or at the semiconductor/dielectric interface, resulting in a significant V th positive shift. [128,129] As introduced in Section 2, the positive shift of V th exponentially increases I DS , and therefore, the EQE of phototransistor is easily larger than 100%. The photoresponsivity, R, is defined as [44] (13) where λ is the incident light wavelength, q is the elementary charge, h is the Planck constant, c is the speed of light, and P opt is the incident optical power, respectively.…”

Flexible low-voltage organic phototransistors based on air-stable dinaphtho[2,3-b:2′,3′-f]thieno[3,2-b]thiophene (DNTT)

“…Furthermore, proper biasing sequences and read-out techniques have to be developed, which distinguish these opto-electric transducers from memory-type organic transistors [9,10]. OPTs with various geometries and materials have already been investigated by other research groups within the past years [11][12][13][14][15][16]10]. However, the low-voltage operation of 2-3 V and the large effective mobility greater than 1.2 cm 2 /Vs at channel lengths as short as 1 lm demonstrated in [8] encourage further investigation.…”

“…In order to answer this question, the effect of illumination on the OTFTs has to be studied thoroughly. Furthermore, proper biasing sequences and read-out techniques have to be developed, which distinguish these opto-electric transducers from memory-type organic transistors [9,10]. OPTs with various geometries and materials have already been investigated by other research groups within the past years [11][12][13][14][15][16]10].…”

2D Organic Materials for Optoelectronic Applications

“…For bulk organic semiconductor devices, the photocurrent generation in photodiode involves the exciton formation, diffusion, and dissociation at the interface of a p–n junction, and subsequent carrier collection at the electrodes. In a phototransistor, the photogenerated carriers can either accumulate at the source–drain electrodes to reduce the injection barriers or are trapped at the semiconductor/dielectric interface by electron trap media (p‐type channel transistor) such as PS or SiOH groups on the SiO 2 surface. Both of these results lead to a positive shift (p‐type channel) in threshold voltage; therefore, causing as significant increase in source–drain current.…”