Neuromorphic computing systems that mimic the human brain have recently attracted substantial attention because they allow for the efficient processing of large amounts of data. These systems are composed of neurons and synapses to transfer information; synapses play a particularly important role in transmitting and integrating processed signals between the neurons. The ferroelectric field-effect transistors (FeFETs) can meet the required properties of artificial synaptic devices because the channel current can be controlled with changes in applied gate voltage due to two stable polarization states, meaning that the data can be memorized in various states. In this study, the epitaxial Pb­(Zr0.20Ti0.80)­O3 (PZT) film was grown on La0.67Sr0.33MnO3 (LSMO) buffered SrTiO3 (STO) single crystal substrate using pulsed laser deposition (PLD). As the channel layer, the amorphous indium gallium zinc oxide (a-IGZO) was employed due to its large carrier mobility and good uniformity. The epitaxially grown single-crystal PZT thin film has a residual polarization (P r) value of 20.2 μC/cm2 and the a-IGZO thin film transistor has a carrier mobility of 10.23 cm2/V s. The biological synaptic behaviors were emulated using the fabricated FeFETs based on the PZT and a-IGZO thin film as a gate insulator and channel material, respectively. The synaptic plasticity was analyzed according to the applied voltage pulse condition. The calculated nonlinearity values were 0.00 and 5.41 with 16 pulse numbers and 0.51 and 7.05 with 32 pulse numbers for potentiation and depression, respectively.

As demands for portable electronic devices grow, wireless energy transfer (WET) has started to become readily available. Until now, studies on WET have been mainly based on the electromagnetic (EM)...

Metal halide perovskites have attracted a considerable amount of research attention with significant progress made in the field of optoelectronics. Despite their outstanding electrical characteristics, structural defects impede their potential performance due to the polycrystalline nature of solution‐processed perovskite films. Herein, the effective p‐type doping and defect passivation of phenethylammonium tin iodide ((PEA)2SnI4) perovskite films using xanthate additives as a sulfur source is reported. Sulfur can be introduced to the iodine vacancies mainly at the grain boundaries of the perovskite film, passivating the electrical defects originating from the iodine vacancy and increasing the hole concentration. The Fermi‐level shift toward the valence band maximum of the sulfur‐doped perovskite film is confirmed using ultraviolet photoemission spectroscopy, resulting in p‐type doping. Finally, the electrical performance improvement for the 0.2% sulfur‐doped (PEA)2SnI4 thin‐film transistor with a mobility of 1.45 cm2 V−1 s−1, an on/off ratio of 2.9 × 105 is demonstrated, and hysteresis of 10 V is reduced.

Summary After overcoming 25% of the power conversion efficiency (PCE) for the perovskite solar cells (PSCs), lots of efforts are being put into modularization. In order to advance this, the development of passivation materials that can operate effectively without affecting the cell areas is essential. This study introduces the 1‐decyl‐3‐methylimidazolium bromide (DMIMB), which is an imidazole‐based passivator, working well to form a uniform 2D interlayer on the perovskite surface regardless of the cell area. Consequently, perovskite films that adopted DMIMB 2D interlayer employed perovskite film showed less trap density, more suitable Fermi level, which led to efficiency enhancement up to the PCE of 22.40%. Furthermore, the DMIMP enables the scalable PSCs, resulting in 18.43% of PCE for perovskite solar modules (PSMs) in the active area of 22.6 cm2.

Single crystals of 71PMN-6PZ-23PT [71Pb(Mg1/3Nb2/3)O3-6PbZrO3-23PbTiO3] oriented along the thickness direction (011) with and without Mn doping were grown by a solid-state single-crystal growth method, and pyroelectric properties of the crystals were investigated. Though the pyroelectric coefficient of a Mn doped crystal is not significantly higher than the un-doped one at room temperature (RT), a large enhancement was observed after 0.7 mol. % Mn doping at high temperatures (>100 °C). Furthermore, the FoMs for practical applications at RT, the Mn doped crystal showed large enhancement as compared to the un-doped one. The presented single crystals also yielded excellent figure of merit (FoM) values for pyroelectricity: Fi, Fv, and FD were 3.5 × 10−10 m V−1, 0.02 m2 C−1, and 2.68 × 10−5 Pa−1/2, respectively, at RT. The large pyroelectric response in the Mn-doped single crystal is attributed to the large ferroelectric polarization and low dielectric constant and dielectric loss. The demonstrated pyroelectric response in the Mn-doped 71PMN-6PZ-23PT single crystal shows that it exhibits excellent potential for various thermal sensor applications.