High-Performance Layered Perovskite Transistors and Phototransistors by Binary Solvent Engineering

Abstract

Perovskite materials have displayed remarkable performance when used in photovoltaic devices. In comparison, research on their application in thin-film transistors (TFTs) has been developing slowly. We report reliable high-performance p-channel lead-free layered perovskite phenethylammonium tin iodide TFTs using simple and easily repeatable one-step spin-coating with premixed binary solvents of N,N-dimethylformamide (DMF) and chlorobenzene (CB)/ethyl acetate (EA). CB/EA antisolvent addition facilitates nucleation and formation of films with oriented grain ripening and full coverage. The champion perovskite TFT shows a fivefold increase in the mobility (3.8 cm 2 V −1 s −1 ) and a twofold magnitude increase in the current on/off ratio (∼10 6 ) with improved bias stress stability. Using well-developed n-channel indium gallium zinc oxide TFTs, a complementary inverter with a high gain of ∼30 is demonstrated. Moreover, with efficient charge transport, transistor amplification function, and pronounced photogating properties, the optimized perovskite phototransistors show a remarkably high photodetectivity of up to 3.2 × 10 17 Jones. This simple and highly repeatable method has attracted more attention for fabricating printed high-performance perovskite TFTs and phototransistors beyond energy sector applications.

High-Performance Broadband Phototransistor Based on TeOx/IGTO Heterojunctions

“…The spatial separation of EHPs hinders the rapid recombination of excess carriers, leading to the prolonged falling time and PPC effect. A similar PPC effect has been observed in other absorption materials used in AOS TFTs, such as SnO x , 2D MoS 2 and perovskite. ,, …”

Property Modulation of Two-Dimensional Lead-Free Perovskite Thin Films by Aromatic Polymer Additives for Performance Enhancement of Field-Effect Transistors

“…Afterward, a π-conjugated oligothiophene ligand (4Tm) was used to replace PEA + to feature a stable 2D Sn-based perovskite, which effectively suppressed the oxidation of Sn 2+ and improved the stability of the Sn-based perovskite films and transistors . Recently, the strategies, including self-passivation for grain boundaries by excess PEAI, anti-oxidation by Sn powder, grain crystallization control by solvent engineering, and iodide vacancy passivation through oxygen treatment, have been also reported for realizing high-performance and reliable (PEA) 2 SnI 4 field effect transistors with SiO 2 as dielectrics. , Very recently, a bifunctional small molecule urea has been added into (PEA) 2 SnI 4 to modify the crystallization speed and passivate grain-boundary defects, which enhances the performance of the SiO 2 -gated lead-free perovskite transistors and phototransistors significantly . Obviously, the methods of suppressing the oxidation of Sn 2+ in 2D perovskite materials and transistors are quite similar to those used in 3D ones.…”

Molecular Doping Enabling Mobility Boosting of 2D Sn2+‐Based Perovskites

“…For (PEA) 2 SnI 4 , hole transport is dominated by the thermal activation mode, where the free holes experience multiple trapping at shallow V Sn sites and releasing process, which slows down the movement. [19,20] To improve the charge transport properties of 2D halide perovskites, significant efforts have focused on synthesizing novel A-cation ligands, [15,21,22] blending with 3D perovskites, [23,24] device/interface engineering, [25][26][27][28] additive engineering, [29][30][31][32] and heterovalent atomic doping. [33][34][35] However, these approaches have the disadvantages of complexity, non-uniformity, and indeterminacy.…”