Polymer Electrolyte Dielectrics Enable Efficient Exciton-Polaron Quenching in Organic Semiconductors for Photostable Organic Transistors

Abstract

The photoelectric response of organic field-effect transistors (OFETs) will cause severe photoelectric interference, which hinders the applications of OFETs in the light environment. It is highly challenging to relieve this problem because of the high photosensitivity of most organic semiconductors. Here, we propose an efficient "exciton-polaron quenching" strategy to suppress the photoelectric response and thus construct highly photostable OFETs by utilizing a polymer electrolyte dielectricpoly(acrylic acid) (PAA). This dielectric produces high-density polarons in organic semiconductors under a gate electric field that quench the photogenerated excitons with high efficiency (∼70%). As a result, the OFETs with PAA dielectric exhibit unprecedented photostability against strong light irradiation up to 214 mW/ cm 2 , which far surpasses the reported values and solar irradiance value (∼138 mW/ cm 2 ). The strategy shows high universality in OFETs with different OSCs and electrolytes. As a demonstration, the photostable OFET can stably drive an organic light-emitting diode (OLED) under light irradiation. This work presents an efficient exciton modulation strategy in OSC and proves a high potential in practical applications.

Enhanced Multiwavelength Response of Flexible Synaptic Transistors for Human Sunburned Skin Simulation and Neuromorphic Computation

“…It is worth pointing out that the EPSC are hardly affected by the same UV-light stimulation (Figure 1j) without the presence of AlO X nanoparticles, and there is even a negative photoconductance effect, which is mainly due to the inhibition of the light response by the ion movement. [56] Unlike Figure 1d,k shows the similar A 1 and A 10 during three photostimulation cycles without AlO X , which is consistent with the above results and further indicates that AlO X is beneficial for carrier separation and improving optical response. Additionally, as fabricated flexible intelligent optical synaptic devices can maintain stable EPSC current even under bending radius at 2.5 mm (Figure S4a, S4b, Supporting Information), demonstrating outstanding flexibility.…”

“…[54,55] The light absorption, exciton separation are inhibited and exciton quenching presented when there is only PVDF-HFP, which together results in rapidly declining current. [56,57] By incorporating 5 nm AlO X , the exciton separation process is accelerated, and a detailed mechanism is discussed in Section 2.5. To further demonstrate the universality of this phenomenon, the same structure was constructed on the silicon substrate (Figure S1, Supporting Information), demonstrating that the introduction of AlO X further increased the hysteresis and optical synaptic response characteristics.…”

Improved Hole Injection in Hybrid Light‐Emitting Transistors Incorporating Lithium and Copper(II) Poly(Styrene Sulfonate)

“…Excitons generated in the emissive layer can undergo energy transfer or charge transfer to charge carriers (polaritons) in the highly doped PEDOT:PSS, or other polyelectrolytes, leading to exciton quenching. [ 30,31 ] Furthermore, EL in these devices is generated by electron–hole recombination near the SY/HIL interface; therefore, interface quenching effects observed in photoluminescence experiments with 40 nm thick SY films may underestimate the extent to which in EL is quenched, which may be why the EQE of PEDOT:PSS devices is relatively lower than that would be expected based on the relative PL quenching alone. [ 32 ] Li:PSS S exhibited slightly reduced PL intensity upon increasing the PEDOT:PSS ratio.…”

High mobility n-type organic semiconductors with tunable exciton dynamics toward photo-stable and photo-sensitive transistors

“…It is reported that the photo-generated excitons can be quenched by polarons. 49,[55][56][57][58][59] Moreover, the reorganization energies of PQ-4FP and PQ-4ClP are 364.45 eV and 188.92 eV, respectively (Fig. S12, ESI †).…”