Advanced Nonvolatile Organic Optical Memory Using Self-Assembled Monolayers of Porphyrin–Fullerene Dyads

Abstract

Photo-switchable organic field-effect transistors (OFETs) represent an important platform for designing memory devices for a diverse array of products including security (brand-protection, copy-protection, keyless entry, etc.), credit cards, tickets, and multiple wearable organic electronics applications. Herein, we present a new concept by introducing self-assembled monolayers of donor–acceptor porphyrin–fullerene dyads as light-responsive triggers modulating the electrical characteristics of OFETs and thus pave the way to the development of advanced nonvolatile optical memory. The devices demonstrated wide memory windows, high programming speeds, and long retention times. Furthermore, we show a remarkable effect of the orientation of the fullerene–polymer dyads at the dielectric/semiconductor interface on the device behavior. In particular, the dyads anchored to the dielectric by the porphyrin part induced a reversible photoelectrical switching of OFETs, which is characteristic of flash memory elements. On the contrary, the devices utilizing the dyad anchored by the fullerene moiety demonstrated irreversible switching, thus operating as read-only memory (ROM). A mechanism explaining this behavior is proposed using theoretical DFT calculations. The results suggest the possibility of revisiting hundreds of known donor–acceptor dyads designed previously for artificial photosynthesis or other purposes as versatile optical triggers in advanced OFET-based multibit memory devices for emerging electronic applications.

Chirality‐Induced Spin Selectivity: An Enabling Technology for Quantum Applications

“…The technique has been extensively used in the study of silicon materials, for example, photovoltaic devices, and has been suggested as a potential scheme to readout coherent spin states of quantum bits in the semiconductor-based quantum computer concept. [211] The OFET approach discussed above [205] is here extended to qubit measurements with separation between the qubit states and the charge carriers, allowing retention of the spin coherence properties of molecular qubits. One challenge for implementing this readout scheme is the OFET detection of the electric dipole field of the CT state instead of the full charge of a memory element.…”

“…Along this line, very recent work has demonstrated that monolayers of D/A porphyrin–fullerene dyads can act as light‐responsive triggers modulating the electrical characteristics of OFETs ( Figure a). [ 205 ] The operational mechanism of these devices has been described as follows. After the absorption of photons by D, photoinduced ET from D to A occurs, thereby generating a CS state.…”

“…a) Layout fabricated and characterized in ref. [205] based on porphyrin–fullerene dyads anchored to AlOx through carboxylic groups. b) Exemplary OFET device proposed for the spin‐to‐charge conversion based on CISS effect.…”

Efficient OFET-based optical memory and photodetectors using a novel BODIPY dye

“…49,50 More recently, we demonstrated that light-induced isomerization is not needed at all and self-assembled monolayers of the porphyrin-fullerene dyads could enable efficient electrooptical switching of OFETs. 51 While donor-acceptor dyads are known to be highly photoactive, their molecular structures are usually sophisticated and the synthesis is challenging. Therefore, a promising research direction to simplify the structure of the memory OFETs and make their components less expensive would be using some simple organic dyes as receptor components at the semiconductor/dielectric interface instead of donor-acceptor dyads or photochromic molecules.…”

Improving the Photoresponse of Transistor Memory Using Self-Assembled Nanostructured Block Copolymers as a Photoactive Electret

“…Precise control over the alignment of functional materials is highly desirable in a broad variety of applications including sensors, biomedical electronics, and energy and data storage. − Extensive research studies have focused on the photosensitive materials combined with their nanoscale self-assembly in new optoelectronics. − Utilizing the versatility and compatibility, prototypes of electronic devices based on a field-effect transistor (FET) architecture were generally reported. − Recently, of increasing interest is the phototransistor memory featuring an additional electret for storing and processing optical signals over long-distance transmission with wide bandwidth, high-density data storage, low-power consumption, as well as orthogonal operation in optical/electrical. Therefore, phototransistor memory is regarded to play a pivotal role in exploring next-generation optical communication systems and artificial intelligence. − To date, various materials such as nanocomposites, organic–inorganic hybrid perovskites, transition metal dichalcogenides, and liquid-crystalline materials , have been developed for the functional assembly of phototransistors.…”