Facile and low-cost mechanical techniques for the fabrication of solution-processed polymer and perovskite thin film transistors

Abstract

Low-temperature solution-processed polymer and perovskite thin film field effect transistors (FETs) are attractive, as they are compatible with flexible and printed electronics. Given that chemical treatment of the FET channel is expensive and tedious, and sometimes damages the underneath (dielectric) solution-processed layers, in this work, two facile and scalable mechanical treatment techniques are proposed. In the case of polymer FET, the wet spun film was excited by ultrasonic vibration imposed on the substrate. It is demonstrated that the micromixing effect induced by the ultrasonic radiation results in disentanglement, reorganization, and recrystallization of the polymer chains in the wet film. Ultrasonic vibration also improves the film leveling and uniformity and enhances the charge mobility of the channel of the polymer FET. In the case of the perovskite FET, we found that nitrogen blowing over the spun sample of the perovskite solution is a facile, yet effective substitution for the conventional anti-solvent treatment, commonly used to control the solvent evaporation rate. By nitrogen blowing, we achieved a uniform film of perovskite deposited on a solution-processed dielectric layer with domain sizes up to several hundreds of nanometers. By applying these techniques, the linear charge mobility of 0.041 cm 2 Vs −1 and 0.055 cm 2 Vs −1 were obtained for polymer and perovskite FETs under illumination, respectively. It is shown that while the performance of the polymer FET is only slightly sensitive to illumination, the perovskite FET performs well only under illumination.

The Cs2AgRhCl6 Halide Double Perovskite: A Dynamically Stable Lead-Free Transition-Metal Driven Semiconducting Material for Optoelectronics

“…The computed absorption coefficient curves of A 2 AgRhCl 6 show an onset around 1.1 and 1.3 eV; these are consistent with the SCF bandgaps predicted with SCAN-rVV10 ( Table S2). The Tauc plot, Figure 5B, provides similar insight, since it is often used to extract the bandgaps from experimental absorption spectra (Eom et al, 2017;Tang et al, 2017;Habibi and Eslamian, 2018;Ji et al, 2018). The peak feature in the visible region with an appreciable absorption coefficient is a strong indication that A 2 AgRhCl 6 are potential candidates for possible optoelectronic applications.…”

Application of Perovskite‐Structured Materials in Field‐Effect Transistors

“…Thin-Film: CH 3 NH 3 PbI 3−x Cl x [32,33,104,105,110,111,113,[120][121][122] has been investigated as semiconductor in FETs. Chin et al [102] fabricated a FET by using CH 3 NH 3 PbI 3 as channel and 500 nm SiO 2 layer as the dielectric layer.…”

“…[107] Additionally, Zeidell et al fabricated a FET device by using MAPbI 3−x Cl x film as the channel and SiO 2 as the gate dielectric. [122] Habibi et al [121] fabricated a FET device using nitrogen blowing treated CH 3 NH 3 PbI 3 as the semiconductor layer, poly(4-vinyl phenol): 4,4-(hexafluoroisopropylidene) diphthalic anhydride (PVP:HDA) as the dielectric layer and Au as the source and drain. Equal hole and electron mobilities of 10 cm 2 V −1 s −1 was achieved at room temperature, which is owing to large grain size and passivation of grain boundaries by the formation of solvent complexes.…”

“…The devices showed ambipolar transport behavior. [121] Hysteresis Phenomenon: Perovskite thin-film transistors typically show a strong hysteresis, which limits a comprehensive interpretation of the charge transport behavior and the examination of the charge carrier mobility. [103] Microplates: Li et al [110] investigated the size-dependent phase transitions of CH 3 NH 3 PbI 3 microplates.…”

“…Equal hole and electron mobilities of 10 cm 2 V −1 s −1 was achieved at room temperature, which is owing to large grain size and passivation of grain boundaries by the formation of solvent complexes. [32,104,107,[109][110][111]113,121,122] The extracted mobility would fluctuate significantly based on measurement conditions, such as sweeping direction and sweeping rate. The FET devices were fabricated by using individual CH 3 NH 3 PbI 3 microplates as the semiconducting layer, two prefabricated Cr/Au electrodes as the source-drain, and 300 nm SiO 2 as gate dielectric layer.…”